Chronic Diarrhea – Causes, Symptoms, Diagnosis, Treatment

Chronic diarrhea is defined as the passage of loose or liquid stools, watery stools three or more times a day for at least 4 weeks and urgent need to evacuate or feelings of abdominal discomfort, or increased frequency of these, lasting more than 4 weeks.[rx,rx] Stool consistency is determined by the relationship between faecal water and the water-holding capacity of insoluble faecal solids. As stools consist predominantly of water (60–85%), consistency is difficult to quantify, and for this reason stool weight is used as a reasonable indirect estimation of consistency. Diarrhoea, therefore, can be defined by the weight or volume of stools measured over 24–72h (on average, 2–3 days). The normal weight of stool output over a 24-h period in children and adults is less that 200g; thus, stool weight >200g/24h is an objective definition of diarrhoea. However, it is important to note that up to 20% of patients with liquid diarrhoea, and thus a lower stool weight, are excluded from this definition.

Diarrhea that lasts for more than 2-4 weeks is considered persistent or chronic. In an otherwise healthy person, chronic diarrhea can be a nuisance at best or become a serious health issue. For someone who has a weakened immune system, chronic diarrhea may represent a life-threatening illness.

Types of Chronic Diarrhea

Chronic diarrhea is extremely broad. Categorizing the type of diarrhea will help to narrow down the underlying cause.

Watery Diarrhea

 Osmotic diarrhea

  • Osmotic laxative use (magnesium, phosphate, or sulfate ingestion)
  • Carbohydrate malabsorption (lactose, fructose)
  • Celiac disease
  • Sugar alcohols (mannitol, sorbitol, xylitol)


  • Alcoholism
  • Bacterial enterotoxins such as cholera
  • Bile acid malabsorption
  • Crohn disease in early ileocolitis
  • Hyperthyroidism
  • Medications (quinine, antibiotics, antineoplastics, biguanides, calcitonin, digitalis, colchicine, prostaglandins, ticlopidine)
  • Microscopic colitis
  • Neuroendocrine tumors (gastrinoma, VIPoma, carcinoid tumors, mastocytosis)
  • Nonosmotic laxatives (senna, docusate sodium)


  • Irritable bowel syndrome

Fatty Diarrhea

Malabsorption syndromes

  • Medications (orlistat, acarbose)
  • Gastric bypass
  • Celiac sprue
  • Mesenteric ischemia
  • Parasites (Giardia)
  • Short bowel syndrome
  • Small bowel bacterial overgrowth (SIBO)
  • Tropical sprue
  • Whipple disease
  •  Maldigestion
    • Hepatobiliary disorders
    • Inadequate luminal bile acid
    • Pancreatic insufficiency

Inflammatory Diarrhea

Inflammatory bowel disease

  • Crohn disease
  • Ulcerative colitis
  • Diverticulitis
  • Ulcerative jejunoileitis
  • Invasive infections
    • Clostridium difficile colitis
    • Bacterial infections (tuberculosis, yersiniosis)
    • Parasites (Entamoeba)
    • Ulcerating viral infections (cytomegalovirus, herpes simplex virus)
  • Neoplasms

    • Colon cancer
    • Lymphoma
    • Villous adenocarcinoma
  • Radiation colitis
Definitions of diarrheal illnesses.
Diarrhea The most commonly recognized definition of diarrhea is based on World Health Organization parameters and
define diarrhea by the passage of 3 or looser than normal stools in the preceding 24-hour period. An episode
of diarrhea is defined as lasting 1 day or more and usually ends after at least 2 days without diarrhea.
Acute diarrhea Episode of self-limiting diarrhea with acute onset, typically lasting 5 to 7 days. In most cases, it is due to an
intestinal infection and may be combined to fever and vomiting, meeting the definition of acute gastroenteritis.
Acute diarrhea may be also related to extra-intestinal infections (i.e. urinary infection, viral respiratory
infections), food-poisoning, iatrogenic intestinal damage (i.e. chemotherapy, radiotherapy) or other intestinal
and extra-intestinal diseases such as acute appendicitis.
Prolonged diarrhea Acute onset diarrhea lasting from 7 to 14 days not covering the definition of persistent diarrhea. It is usually
due to persistent infections or to post-infectious intestinal damage (i.e. carbohydrate malabsorption, small
intestine bacterial overgrowth) that may prolong the duration of diarrhea behind the expected time.
Some experts refer to this as acute-protracted diarrhea.
Persistent diarrhea Diarrhea lasting 14 days or more, usually associated with weight loss, ultimately leading to severe nutritional
impairment and that may require clinical nutrition.
The classical definition of persistent diarrhea was intended to exclude some causes of chronic diarrhea such
as celiac disease or inflammatory bowel diseases.
Chronic diarrhea In many contexts chronic diarrhea is a synonymous of persistent diarrhea. The World Health Organization
uses this definition rather than persistent diarrhea.
However, chronic diarrhea usually does not have an acute onset and is the manifestation of structural and
inflammatory bowel disorders.
Some experts refer to chronic diarrhea in case of episodes lasting more than 4 weeks.
Post-infectious diarrhea Acute onset diarrhea lasting 7 to 14 days and following an episode of acute gastroenteritis. This definition is
covered by prolonged diarrhea.
Intractable diarrhea Non-infectious diarrhea lasting more than 14 days, intractable despite extensive hospital therapy.
Typical of young infants, usually below 3 months (but not only). Typically needs intravenous fluids or clinical
nutrition and is related to high mortality.
Congenital diarrhea Congenital diarrhea is an inherited enteropathy with a typical onset early in life. For many of these conditions,
severe chronic diarrhea represents the main clinical manifestation, while in others, diarrhea is only a
component of a more complex multi-organ or systemic disease.

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Classification of chronic diarrhoea.

Chronic watery diarrhoea
1. Osmotic
Osmotic laxatives (Mg+2, PO, SO4−2)
Carbohydrate malabsorption
Excessive consumption of poorly absorbed carbohydrates
Sorbitol and mannitol (“sugar-free” chewing gum)
Fructose (fruit, soft drinks)
2. Secretory
Congenital chloride diarrhoea
Bacterial enterotoxins
Bile acid malabsorption
Inflammatory bowel disease
Ulcerative colitis
Crohn disease
Microscopic colitis
Laxative abuse
Food allergies
Heavy metal poisoning
Post-vagotomy diarrhoea
Post-sympathectomy diarrhoea
Diabetic autonomic neuropathy
Irritable bowel syndrome
Faecal impaction
Faecal incontinence
Endocrine disorders
Addison disease
Carcinoid syndrome
Other neoplasms
Colorectal cancer
Small bowel lymphoma
Secretory villous adenoma of the rectum
Idiopathic secretory diarrhoea
Others: amyloidosis
Chronic inflammatory diarrhoea
Inflammatory bowel disease
Ulcerative colitis
Crohn disease
Ulcerative jejunoileitis
Infectious diseases
Bacteria: Shigella, Salmonella, Campylobacter, Yersinia, Clostridium difficile
Viruses: herpes simplex, CMV
Parasites: amoebiasis, strongyloidesstercoralis
Ischaemic colitis
Radiation colitis
Colorectal cancer
Chronic diarrhoea with steatorrhoea
Enteric causes
Mucosal diseases: coeliac, Whipple, giardiasis, lymphoma, Crohn, radiation enteritis, gastrointestinal lymphangiectasia, amyloidosis, eosinophilic gastroenteritis, tropical sprue, sprue, collagenous colitis.
Short bowel syndrome
Bacterial overgrowth
Chronic mesenteric ischaemia
Maldigestion syndromes
Exocrine pancreatic insufficiency
Low bile acid levels in the intestinal lumen


Causes of Chronic Diarrhea

Common diseases and disorders that cause chronic diarrhea include

  • Infections of the digestive tract – Infections from harmful viruses, bacteria, or parasites sometimes lead to chronic diarrhea. Children may become infected through contaminated water, beverages, or food; or through person-to-person contact. After infection, some children have problems digesting carbohydrates such as lactose or proteins in foods such as milk, milk products, or soy. These problems can cause prolonged diarrhea—often for up to 6 weeks—after an infection. Also, some bacterial and parasitic infections that cause diarrhea do not go away quickly without treatment.
  • Celiac disease – Celiac disease is a digestive disorder that damages the small intestine. The disease is triggered by eating foods containing gluten. Gluten is a protein found naturally in wheat, barley, and rye. Gluten is common in foods such as bread, pasta, cookies, and cakes. Celiac disease can cause chronic diarrhea in children of any age.
  • Functional GI disorders – In functional GI disorders, symptoms are caused by changes in how the digestive tract works. Children with a functional GI disorder have frequent symptoms, yet the digestive tract does not become damaged. Functional GI disorders are not diseases; they are groups of symptoms that occur together. Two functional GI disorders that cause chronic diarrhea in children are toddler’s diarrhea and irritable bowel syndrome (IBS).
  • Toddler’s diarrhea – also called functional diarrhea, or chronic nonspecific diarrhea of childhood—is a common cause of chronic diarrhea in toddlers (ages 1 to 3), and preschool-age children (ages 3 to 5). Children with toddler’s diarrhea pass four or more watery or loose stools a day and do not have any other symptoms. They typically are growing well, gaining weight, and are healthy. Toddler’s diarrhea develops between the ages of 6 months and 3 years, and it usually goes away on its own by the time children begin grade school. Researchers think that drinking too many sugar-sweetened beverages, especially those high in high-fructose corn syrup and sorbitol, may cause a toddler’s diarrhea.
  • IBS – The most common symptoms of IBS are abdominal pain, discomfort, or cramping; with diarrhea, constipation, or both. The pain or discomfort of IBS typically gets better with the passage of stool or gas. IBS does not cause symptoms such as weight loss, vomiting, or blood in the stool. IBS is a common cause of chronic diarrhea in grade school-age children and adolescents. Doctors rarely diagnose IBS in younger children because younger children are not able to report symptoms of IBS such as abdominal pain or discomfort.
  • Food allergies and intolerances – Food allergies, lactose intolerance, fructose intolerance, and sucrose intolerance are common causes of chronic diarrhea.
  • Food allergies – Milk, milk products, and soy allergies are the most common food allergies that affect the digestive tract in children. Food allergies usually appear in the first year of life. Many children outgrow allergies to milk, milk products, and soy by age 3. Allergies to other foods such as cereal grains, eggs, and seafood may also affect the digestive tract in children.
  • Lactose intolerance – Lactose intolerance is a common condition that may cause diarrhea after eating foods or drinking beverages that contain milk or milk products. Low levels of lactase—the enzyme that helps digest lactose—or lactase deficiency, and malabsorption of lactose cause lactose intolerance. The most common type of lactase deficiency in children develops over time, beginning after about age 2, when a child’s body begins to produce less lactase. Children who have lactase deficiency may not experience symptoms of lactose intolerance until they become older teenagers or adults. Infants—newborns to age 1—rarely have lactose intolerance at birth. However, premature infants may experience lactose intolerance for a short time after birth. People sometimes mistake milk allergy, which can cause diarrhea in infants, for lactose intolerance.
  • Fructose intolerance – Fructose intolerance is a condition that may cause diarrhea after eating foods or drinking beverages that contain fructose, a sugar found in fruits, fruit juices, and honey. Fructose is added to many foods and soft drinks as a sweetener called high-fructose corn syrup. Fructose malabsorption causes fructose intolerance. The amount of fructose that a child’s body can absorb varies. A child’s ability to absorb fructose increases with age. Some children may be able to tolerate more fructose as they get older.
  • Sucrose intolerance – Sucrose intolerance is a condition that may cause diarrhea after eating foods or drinking beverages that contain sucrose, also known as table sugar or white sugar. Sucrose malabsorption causes sucrose intolerance. Children who are sucrose intolerant lack the enzyme that helps digest sucrose. Most children with sucrose intolerance are better able to tolerate sucrose as they get older.
  • Inflammatory bowel disease (IBD) – The two main types of IBD are Crohn’s disease and ulcerative colitis. These disorders can affect children at any age. However, they commonly begin in the grade school years or in adolescence.
  • Small intestinal bacterial overgrowth (SIBO) – SIBO is an increase in the number of bacteria or a change in the type of bacteria in your small intestine. SIBO is often related to diseases that damage the digestive system such as Crohn’s disease.
  • Irritable Bowel Syndrome (IBS) – This is defined as chronically abnormal bowel habits (diarrhea and/or constipation) associated with abdominal pain in the absence of any pathology.  Females are more likely to be diagnosed with IBS than males. Symptoms of IBS are usually worsened by stress. The symptoms are generally described as crampy lower abdominal pain with associated diarrhea, constipation, or alternating diarrhea and constipation.  Symptoms are often alleviated by defecation, although this is not necessary for diagnosis. For patients with diarrhea, usually describe their bowel movements as being small or moderate amounts of loose stool. Usually, bowel movements are associated with urgency.
  • Medications – Certain medications are known to induce diarrhea in patients. Currently, there are greater than 700 drugs that are associated with diarrhea.  Medical practitioners must look to the addition of new medications which may be associated with diarrhea.  When the offending agent is discontinued, diarrhea may stop within as little as a day but may take longer if there is an injury to the intestinal mucosa.  Patients who are receiving chemotherapy can have diffuse or segmental colitis.  Olmesartan producing a sprue-like enteropathy was first described in 2012.  In this disease state, the intestinal mucosa will mimic the findings of celiac sprue, but the patients are not actually insensitive to gluten.
  • Crohn Disease – Crohn’s disease is an inflammatory bowel disease that is an autoimmune disease.  Typical symptoms include diarrhea (often associated with blood and/or mucus), abdominal pain, and signs of bowel obstructions.  Perirectal fistulas may be present on the exam which may help to clue the physician into the diagnosis. Although this disease can present anywhere in the gastrointestinal tract, it most commonly affects the terminal ileum.
  • Ulcerative Colitis – Ulcerative colitis is the other major component of inflammatory bowel disease.  This disease has an unknown etiology. Patients often present with abdominal pain, diarrhea, and hematochezia.  Other signs that may aid diagnosis are weight loss and pallor secondary to anemia.
  • Microscopic Colitis – This is a common cause of chronic watery diarrhea.  There are two subtypes of microscopic colitis: collagenous and lymphocytic colitis.  It is diagnosed based on an endoscopic biopsy.
  • Celiac Disease – This disease process occurs in individuals who develop an immune-mediated reaction triggered by the ingestion of gluten.  Celiac disease occurs in only about 1% of the population, but the incidence is rising. Symptoms include abdominal cramping, diarrhea, and weight loss.  Diagnosis requires a biopsy of the intestine showing villous atrophy. Most patients will produce the antibody against tissue transglutaminase.
  • Chronic Pancreatitis – Pancreatic enzymes are essential for the proper digestion of fats, proteins, and carbohydrates.  Patients with chronic pancreatitis will develop recurrent bouts of acute pancreatitis and chronic abdominal pain.  Chronic pancreatitis will eventually lead to scarring and fibrosis of the pancreas, which will decrease the number of pancreatic enzymes, and malabsorption.  This will lead to steatorrhea and weight loss.
  • Lactose Intolerance – The ability to digest lactose comes from an enzyme present in the intestine called lactase.  This allows the lactose to be broken down into simple sugar and be absorbed. When this enzyme is absent, the lactose is not able to be absorbed by the intestine.  This will increase the osmolality within the lumen of the intestine producing watery diarrhea shortly after the ingestion of lactose-containing foods.
  • Malabsorption Syndromes – This term is very nonspecific and encompasses any disorder where the intestine has a decreased ability to absorb nutrients while not requiring intravenous supplementation for health and/or growth.
  • Post-cholecystectomy Diarrhea – Diarrhea after a cholecystectomy occurs in up to 12% of patients.  Over time, symptoms generally resolve on their own without intervention. Since the gallbladder is removed, the bile produced by the liver directly enters the colon instead of being stored.  The increased amount of bile acids in the colon produces diarrhea.
  • Chronic Infections – Certain long-lasting infections of the gastrointestinal tract can be linked to chronic diarrhea.  A few of these infections include C. difficile, Vibrio cholera, Salmonella, Shigella, Entamoeba histolytica, E. Coli, Giardia, Cryptosporidium, Whipple Disease, and Cyclospora. A clinician should always have a suspicion of an infectious cause of diarrhea. Risk factors include travel and immunosuppression.

Symptoms of Chronic Diarrhea

The main symptom of chronic diarrhea is passing loose, watery stools three or more times a day for at least 4 weeks.

Depending on the cause, children with chronic diarrhea may also have one or more of the following symptoms:

  • bloody stools
  • chills
  • fever
  • loss of control of bowel movements
  • nausea or vomiting
  • pain or cramping in the abdomen

Chronic diarrhea may cause malabsorption and may lead to dehydration.

Chronic diarrhoea: signs, symptoms and analytical findings suggestive of an organic cause.

Blood in stools
Recent weight loss (>5kg) (in absence of concomitant depression)
Recent onset of symptoms, or change in the characteristics of previous symptoms
Onset at an advanced age (≥50 years)
Family history of colorectal cancer or polyps
Nocturnal diarrhoea
Diarrhoea persists after fasting
High-volume stool output or steatorrhoea
Weight of stool output over 24h >400g/day
Abnormalities on physical examination (pallor, hepatosplenomegaly, adenopathies, abdominal mass, etc.)
Anaemia, macrocytosis, hypoprothrombinaemia, hypoalbuminaemia or other laboratory findings (e.g. elevated ESR or C-reactive protein)
Positive faecal occult blood test, elevated faecal calprotectin

The infection often starts suddenly with projectile vomiting or severe diarrhea. It is considered to be diarrhea if you have more than three very loose or liquid bowel movements within 24 hours. People who have diarrhea often have a stomach aches, cramps, and bloating too. Diarrhea and nausea are sometimes also accompanied by fever, headache, and joint pain. Dizziness and feeling faint could be signs that your body has lost too much liquid and salts (electrolytes). If that happens, immediate medical attention is needed. Other reasons to seek medical help for diarrhea include:

  • No improvement after 48 hours
  • High fever
  • Blood in your poo (it has red blood in it or is black)
  • The mucous coating on the poo
  • Severe pain

Diagnosis of Chronic Diarrhea

When you see the doctor you will first be asked

  • whether your symptoms started suddenly or gradually,
  • what your poo looks like (consistency and appearance),
  • how long and how frequently you have had diarrhea,
  • whether you also have symptoms such as stomach ache, vomiting or fever, and
  • what you had to eat before getting diarrhea.

It is also important for them to know

  • whether you have been traveling recently,
  • what medications you were or are taking,
  • whether you have any diagnosed allergies or intolerances, and
  • whether you have a chronic disease, such as diabetes.

If you have bloody or persistent diarrhea, a sample of your stool (poo) or blood may be needed to find out what kind of infection you have. The same applies if there is mucus in diarrhea.

Your doctor will ask about your medical history, symptoms, and any medicines you take. Your doctor will also perform a physical exam and may order an upper gastrointestinal (GI) endoscopy with biopsies or other tests.

History and physical exam vary widely from patient to patient depending on the severity and etiology of the disease.  The physical exam is often normal in patients with chronic diarrhea; however, signs of unintentional weight loss points towards a more severe disease. Although history and physical exam will rarely lead to a specific cause of chronic diarrhea, it is an integral part of any patient encounter. It is important to have the patient describe their diarrhea. Specific descriptions such as hematochezia, mucus in the stool, or steatorrhea help narrow the differential diagnosis greatly. Some specific physical exam signs may clue the examiner towards a diagnosis.

For all patients complaining of chronic diarrhea, a thorough history and physical exam are necessary.  The following laboratory testing should also take place for every patient with chronic diarrhea:

  • Complete blood count with differential to examine for infection and anemia
  • Erythrocyte sedimentation rate and C-reactive protein to look for infections
  • Thyroid function tests to screen for hyperthyroidism
  • Complete metabolic profile to search for electrolyte abnormalities, renal function
  • Total protein and albumin to look for signs of protein malnutrition
  • Stool occult blood to look for a gastrointestinal bleed

If the patient has any alarming symptoms, a referral for an endoscopy is necessary.  Alarm symptoms include

  • Symptom onset after age 50
  • Rectal bleeding/melena
  • Nocturnal pain or diarrhea
  • Progressive abdominal pain
  • Unexplained weight loss, fever, or other systemic symptoms
  • Laboratory abnormalities such as iron deficiency anemia, elevated ESR/CRP, elevated fecal calprotectin, or fecal occult blood
  • First degree relative with inflammatory bowel disease or colorectal cancer

If patients do not have alarming symptoms, stool laboratory assessment is a recommendation.  If the patient has recent antibiotic use, checking the stool for C. difficile toxin is warranted; C. difficile toxin should be reviewed on all patients with chronic diarrhea, regardless of antibiotic use, if their diarrhea classically fits the description of C. difficile: watery diarrhea occurring 3 or more times per day.

When categorizing the stool, it is essential to check for the following labs:

  • Stool electrolytes
  • Fecal leukocytes (fecal lactoferrin or fecal calprotectin are a substitute in place of fecal leukocytes)
  • Fecal chymotrypsin and elastase
  • Occult blood
  • Stool fat (48 to 72 hour timed collection is ideal)

While chronic diarrhea has a very broad differential diagnosis, categorizing the stool can help narrow down the list. Fecal leukocytes/calprotectin/lactoferrin are markers of inflammation.  The presence of these markers will point towards inflammatory diarrhea, such as Crohn’s disease, or ulcerative colitis.

Fecal chymotrypsin and elastase are pancreatic enzymes that can present in the stool in the setting of pancreatic insufficiency.  These two tests do not definitively diagnose pancreatic insufficiency.  If these are positive on stool testing, the physician should check blood tests for pancreatic enzymes, and potentially refer to a gastroenterologist for further studies.

For patients with watery diarrhea, stool electrolytes will further categorize their diarrhea into either osmotic diarrhea or secretory diarrhea based on the calculation of the stool osmotic gap.  The calculation is as follows:

  • 290 mOsm/kg – 2(Na[feces]+K[feces])

If the result of the above formula is less than 50 mOsm/kg, then the diarrhea is secretory.  If the result is greater than 75 mOsm/kg, then the diarrhea is osmotic.

Lab Test

  • Upper GI endoscopy – Upper GI endoscopy is a procedure in which a doctor uses an endoscope—a flexible tube with a camera—to see the lining of your upper GI tract, including your esophagus, stomach, and duodenum. During upper GI endoscopy, a doctor obtains biopsies by passing an instrument through the endoscope to take small pieces of tissue from your stomach lining. A pathologist will examine the tissue with a microscope. Doctors may use upper GI endoscopy to diagnose gastritis or gastropathy, determine the cause, and manage complications.
  • Blood tests – Doctors may use blood tests to check for other causes of gastritis or signs of complications. For a blood test, a health care professional will take a blood sample from you and send the sample to a lab.
  • Stool tests – Doctors may use stool tests to check for H. pylori infection and for blood in your stool, a sign of bleeding in your stomach.
  • Timed stool collection – Neither patients nor laboratory technicians relish in the timed stool test (48–72 hrs of stool collection; normal stool weight is 200g/24 hrs with less than 7g fat), yet this is the standard for assessing steatorrhea. A fresh stool sample is necessary to differentiate secretory from osmotic diarrhea. Stool weight greater than 1000g/24 hrs leads to a different diagnostic approach (a search for a possible neuroendocrine cause) than a value of 300g/24 hrs. Approximately 25% of patients referred specifically for a diarrhea evaluation actually have normal stool weight (Sellin J, unpublished observations). The 48 hr stool collection test can also be used to measure fecal bile acids.
  • Blood tests for neuroendocrine tumors – hormone-secreting tumors are rare causes of secretory diarrhea, typically detected by measuring serum levels of chromogranin, gastrin, vasoactive intestinal polypeptide, or calcitonin, as well as urine level of 5-hydroxy indole acetic acid. However, due to the rarity of these tumors and low pretest probability, many positive results from these tests (especially borderline results) turn out to be false positives. These tests should therefore almost never be considered early in the course of an evaluation.
  • Urea breath test – Doctors may use a urea breath test to check for H. pylori infection. For the test, you will swallow a capsule, liquid, or pudding that contains urea that is “labeled” with a special carbon atom. If H. pylori is present, the bacteria will convert the urea into carbon dioxide. After a few minutes, you will breathe into a container, exhaling carbon dioxide. A health care professional will test your exhaled breath. If the test detects the labeled carbon atoms, the health care professional will confirm an H. pylori infection in your digestive tract.
  • Upper GI series – Doctors may use an upper GI series to check for signs of gastritis or gastropathy. An upper GI series is a procedure in which a doctor uses x-rays and a chalky liquid called barium to view your upper GI tract.
  • MR enterography – is recommended for evaluation of small bowel abnormalities depending on availability (Grade of evidence level 1, Strength of recommendation strong).
  • Video capsule endoscopy (VCE) – is recommended for assessing small bowel abnormalities depending on local availability (Grade of evidence level 1, Strength of recommendation strong).
  • Small bowel barium follow-through or barium enteroclysis – for the evaluation of small bowel abnormalities due to its poor sensitivity and specificity (Grade of evidence level 5, Strength of recommendation strong).
  • Fecal elastase testing – when fat malabsorption is suspected. We do not recommend PABA testing (Grade of evidence level 1, Strength of recommendation strong).
  • MRI (rather than CT) – is recommended for assessing structural anomalies of the pancreas in suspected chronic  chronic diarrhea (Grade of evidence level 2, Strength of recommendation strong).

    Treatment for Chronic Diarrhea

    How doctors treat chronic diarrhea depends on the cause. Doctors may be able to reduce or stop chronic diarrhea by treating the cause.

    A bland ‘BRAT’ diet including bananas, toast, oatmeal, white rice, applesauce, and soup/broth is well tolerated and may improve symptoms.  Anti-diarrheal therapy with anti-secretory or anti-motility agents may be started to reduce the frequency of stools.

    Non Pharmacological

    • Food allergies – If your child has a food allergy, his or her doctor will recommend avoiding foods that trigger the allergy. Keeping a diary of what your child eats and drinks and his or her bowel habits will help your child’s doctor find out what foods trigger the allergy.
    • Lactose intolerance – If your is lactose intolerant, his or her doctor will recommend reducing or avoiding foods and beverages that contain milk or milk products. Most with lactose intolerance can tolerate some amount of lactose in what they eat or drink. The amount of change needed in what a child eats or drinks depends on how much lactose a child can consume without symptoms. Your child’s doctor may recommend dietary supplements that contain lactase, the enzyme that helps digest lactose. Your child’s doctor may also recommend calcium supplements.
    • Fructose intolerance – If is fructose intolerant, will recommend reducing or avoiding foods and beverages that contain fructose.
    • Sucrose intolerance – If is sucrose intolerant, his or her doctor will recommend reducing or avoiding foods and beverages that contain sucrose.


    Drugs used in Treatment of Chronic Watery Diarrhea

    Drug class Agent Dose
    Opiates (μ-opiate receptor-selective)
    Diphenoxylate 2.5–5 mg, 4 times/day
    Loperamide 2–4 mg, 4 times/day
    Codeine 15–60 mg, 4 times/day
    Opium tincture 2–20 drops, 4 times/day
    Morphine 2–20 mg, 4 times/day
    Eluxadoline 100 mg twice daily (μ-opioid agonist and δ-opioid antagonist) for IBS-D
    Adrenergic α2 receptor agonist
    Clonidine 0.1–0.3 mg 3 times/day; Weekly patch
    Somatostatin analog
    Octreotide 50–250 μg 3 times/day (subcutaneously)
    Bile acid-binding resin
    Cholestyramine 4 g daily or up to 4 times/day
    Colestipol 4 g daily or up to 4 times/day
    Colesevelam 1875 mg up to twice daily
    Fiber supplements
    Calcium polycarbophil 5–10 g daily
    Psyllium 10–20 g daily
    Soluble fiber Pectin 2 capsules before meals
    Calcium 1000 mg twice or 3 times daily
    Serotonin 5-HT3 receptor antagonists
    Alosetron 0.5–1.0 mg twice daily
    Ondansetron 2–8 mg twice daily
    • Azithromycin – in a single dosage 0r ciprofloxacillin in a double dosage for 7 days . In a randomized trial,  Azithromycin was found to be clinically and bacteriological successful in 82% and 94% of patients treated respectively. Cefixime and ceftibuten can be used as first-line to treat in due to widespread resistance to commonly used antibiotics. The alternative regimen includes pivmecillinam, an extended-spectrum penicillin is effective in decreasing diarrhea duration and eradication of chronic diarrhea organisms in the stool.
    •  Loperamide – is a safe mu-receptor agonist used to decrease gut peristalsis. Loperamide is a safe mu-receptor agonist used to decrease gut peristalsis and decrease the gut motility. Loperamide is not suitable for children under the age of twelve years, and racecadotril is prescription-only for children.
    • Nitazoxanide – is a broad-spectrum antimicrobial agent with activity against protozoa, nematodes, cestodes, trematodes, and bacteria, with a favorable safety profile , . It is effective in childhood cryptosporidiosis but not consistently in undernourished children or in HIV-infected patients . Anecdotal cases of children successfully treated with nitazoxanide because of PD (<30 days) have been reported . This strategy seems to be effective in select situations, saving time-consuming tests to identify the cause of diarrhea .
    • Cholestyramine – Other medications used for chronic diarrhea include bile acid-binding resins such as cholestyramine.  Clonidine is an alpha2-adrenergic agonist that also slows the intestinal tract, and is an option for diarrhea secondary to opioid withdrawal as well as diarrhea secondary to loss of noradrenergic innervation in patients with diabetes.  The use of this medication has limitations due to the antihypertensive effect. However, this medication may be useful for patients with hypertension and chronic diarrhea.
    • Ceftriaxone – Intra venous or parenteral antibiotics are indicated in children with suspected and proven chronic diarrhoea who have a severe infection with signs of bacteremia including lethargy, temperature >39° C (102.2°F), underlying immune deficiency including AIDS and those unable to take oral medications.  Ceftriaxone is recommended as a single dose or for five days.
    • Anticholinergic medications – can be used to treat diarrhea as well. Tricyclic antidepressants which are used to treat depression or pain can also treat diarrhea.
    • Immunoglobulin – available for intravenous use, may be administered orally (300 mg/kg of body weight) in a single dose. The rationale of passive immunotherapy is based on the demonstration of neutralizing antibodies against all viruses in a medical preparation of immunoglobulins .
    • Cholestyramine – Other medications used for chronic diarrhea include bile acid-binding resins such as cholestyramine.  Clonidine is an alpha2-adrenergic agonist that also slows the intestinal tract, and is an option for diarrhea secondary to opioid withdrawal as well as diarrhea secondary to loss of noradrenergic innervation in patients with diabetes.  The use of this medication has limitations due to the antihypertensive effect. However, this medication may be useful for patients with hypertension and chronic diarrhea.
    • Yeast tablets – Sometimes certain types of yeast tablets (Perenterol) are recommended. These tablets are thought to help the body get rid of germs faster and to support natural gut flora. Charcoal tablets dissolved in water can also be taken to relieve diarrhea symptoms. But there’s a lack of good-quality research in this area so no conclusions can be drawn about the benefits and harms of these treatment options. People who are very ill or have a very weak immune system shouldn’t take yeast tablets.
    • Zinc supplementation – is reported to reduce both the stool volume and stool frequency by 30 percent and is a consideration in severe cases. Although diets such as BRAT (banana, rice, apple, and toast) or bland diet have been proposed to improve the condition and are somewhat better tolerated; no reliable data or prospective studies are available to confirm this, and the assumptions are mostly based on limited studies or personal experiences.

    Foods to avoid

    Fried and greasy foods are usually not well-tolerated in people who have diarrhea. You should also consider limiting high-fiber foods like bran as well as fruits and vegetables that can increase bloating. Foods to avoid include:

    • alcohol
    • artificial sweeteners (found in chewing gum, diet soft drinks and sugar substitutes)
    • beans
    • berries
    • broccoli
    • cabbage
    • cauliflower
    • chickpeas
    • coffee
    • corn
    • ice cream
    • green leafy vegetables
    • milk
    • peas
    • peppers
    • prunes
    • tea

    Foods to eat

    While it might sound counterintuitive to eat if you have diarrhea, eating certain foods can help alleviate your diarrhea symptoms and ensure your health doesn’t worsen from not eating. Stick to low-fiber “BRAT” foods that will help firm up your stool. These include:

    • bananas
    • rice (white)
    • applesauce
    • toast

    Other foods that are usually well-tolerated when experiencing diarrhea include:

    • oatmeal
    • boiled or baked potatoes (with skins peeled)
    • baked chicken with skin removed
    • chicken soup (which also aids in rehydration)


    Probiotics are sources of “good” bacteria that work in your intestinal tract to create a healthy gut environment. They’re essentially live microorganisms that exist in certain foods, including:

    • aged soft cheeses
    • beet kvass
    • cottage cheese
    • dark chocolate
    • green olives
    • kefir
    • kimchi
    • kombucha
    • sauerkraut
    • miso
    • natto
    • pickles
    • sourdough bread
    • tempeh
    • yogurt

    Probiotics also come in powder or pill form.

    • The good bacteria that live in your intestinal tract are necessary for the normal functioning of your gastrointestinal system. They play an important role in protecting your intestines against infection. When your system is changed by antibiotics or overwhelmed by unhealthy bacteria or viruses, you can get diarrhea. Probiotics can help with diarrhea by restoring the balance of bacteria in your gut.
    • Saccharomyces boulardii is a yeast probiotic. While it’s not a bacterium, it acts like one. S. boulardii may improve antibiotic-associated diarrhea. It also seems to provide relief for traveler’s diarrhea. It may help your intestines fight off unwanted pathogens and ensure they’re absorbing nutrients properly. Because it is yeast, it should be used with caution in people with inadequate immune systems.


    Viruses and bacteria can spread through contact with poo, vomit, and contaminated objects, water, or food.

    • This means that it is very important to frequently wash your hands thoroughly with soap if you have acute diarrhea, in order to protect others from infection. Washing your hands also protects you from infection if someone you know is infected. A hand disinfectant can help too. If you have a second bathroom at home, whoever is ill can be the only one to use it.
    • Clothes should be washed at temperatures above 60 degrees Celsius (about 140 degrees Fahrenheit) if possible. It is important to pay attention to hygiene in the kitchen and while preparing food. Anyone with acute diarrhea shouldn’t prepare food for others.
    • When traveling to tropical or subtropical climates, you may need to avoid uncooked, unpeeled fruit and vegetables and not drink tap water. Don’t eat undercooked meat or fish.
    • keeping a food diary and seeing how cutting particular foods from the diet affect the diarrhea
    • discussing the side effects of any current medications with a doctor
    • requesting a change in medications if necessary
    • taking probiotic supplements regularly
    • drinking only clean or filtered water
    • washing the hands both before and after food preparation
    • cleaning and thoroughly cooking meat before eating it
    • washing fresh produce before eating it
    • cleaning kitchen surfaces regularly
    • washing the hands regularly, especially after using the bathroom or coming into contact with a person who is ill


    Complications of shigella infection include intestinal and systemic complications listed below. 

    Intestinal Complications

    • Colon perforation – Very rare and primarily occurs in infants and malnourished patients.  It is associated with Sflexneri and Sdysenteriae 1. 
    • Intestinal obstruction – usually seen in severe disease and Sdysenteriae 1.
    • Toxic megacolon – Usually occurs in Sdysenteriae 1 infection.
    • Proctitis or rectal prolapse – Invasion of shigella organisms into colonic mucosa can lead to rectal prolapse and proctitis in infants and young children.
    • Bacteremia – Common in young children under the age of 5. 
    • Hemolytic-uremic syndrome – Although uncommon, HUS is the most frequent acute kidney injury in young children and infants.
    • Moderate to severe hypovolemia
    • Hyponatremia – Usually associated with Sdysenteriae 1 infection.
    • Leukemoid reaction – Common in children between ages 2-10 years old.
    • Neurologic symptoms – Generalized seizures are the most common neurologic complication. This is usually associated with a higher mortality rate.
    • Reactive arthritis or Reiter syndrome – Uncommon sterile inflammatory arthritis. It is usually caused by Sflexneri infection. Arthritis can occur alone or in conjunction with conjunctivitis and urethritis.
    • Vulvovaginitis – with or without diarrhea-Seen in young girls associated with painless vaginal discharge.
    • Keratitis – Rare but should be considered in a young child with keratitis and a history of recent diarrheal illness.
    • Acute myocarditis – Seen in children with S. Sonnei infection.
    • Weight loss – in adults and other consequences of malnutrition such as increased susceptibility to infections, and increased morbidity and mortality from various disease states. Additionally, in children, malnutrition results in growth failure and poor neurological development
    • Deficiencies of fat-soluble vitamins (A, D, E, and K)
    • Poor bone health resulting in osteopenia, osteoporosis, and fractures (CF, celiac disease)
    • Iron deficiency anemia, zinc deficiency (celiac disease)
    • Dermatitis herpetiformis, non-Hodgkin lymphoma, adenocarcinoma of the upper gastrointestinal tract (celiac disease)
    • Megaloblastic anemia due to B12 deficiency (in terminal ileum disease and SIBO)
    • Pancreatic pseudocyst, ascites, splenic vein thrombosis, diabetes, pancreatic cancer (chronic pancreatitis)
    • Seizure, osteopenia, ataxia, early bruising, headache, hyposplenism, and tetany (celiac disease)
    • Cirrhosis, end-stage liver disease (PBC, PSC), malignancies such as cholangiocarcinoma, colon cancer in PSC

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