Chronic diarrhea is defined as the abnormal passage of ≥3 loose or liquid stools per day for ≥4 week with or without a daily stool weight >200 g/day.
The definition of chronic diarrhea based on symptoms alone will lead to an overlap with functional bowel disorders eg irritable bowel syndrome.
Diarrhea that is continuous or nocturnal and lasting <3 months is more likely due to an organic disease.
The absence of abdominal pain during defecation and presence of weight loss are points against the diagnosis of functional bowel syndrome eg irritable bowel syndrome.

Principles of Therapy

Treatment Trial

  • In some cases, treatment may include stopping a food or drug
    • Lactose-containing foods or drinks
    • Sugar-free products with sorbitol and foods made with fat replacements
    • Drugs such as laxatives and antacids

Indications for Empiric Therapy

  • Initial treatment during diagnostic testing
  • When a diagnosis is strongly suspected and follow-up is available
  • When there is no confirmed diagnosis after testing
  • When a diagnosis has been established but specific treatment is either unavailable or has proven ineffective
  • When comorbidities limit diagnostic investigation
  • When resources are limited



  • Symptomatic treatment may be needed in patients because specific treatment may not be available
  • Antidiarrheals can decrease stool frequency and stool weight along with associated symptoms (eg abdominal cramps)


  • Include natural opioids (eg Codeine, Opium, Morphine) and synthetic opioids (eg Diphenoxylate, Loperamide)
  • The natural opiates are highly potent remedies for diarrhea
    • Patients need to be informed about the abuse potential of these drugs; though in practice, these substances are rarely abused by chronic diarrhea sufferers
  • Synthetic opioids are less potent but usually are adequate to control less severe diarrhea and should be used 1st prior to more potent agents
  • Dose should be started at a low level and titrated up as needed to achieve effectiveness
  • Use of these drugs should be monitored closely

Bismuth Preparations

  • Shown to be effective in acute traveler’s diarrhea but effectiveness in chronic diarrhea has not yet been proven
  • Actions: Bismuth subsalicylate has antisecretory, antibacterial and anti-inflammatory effects

Other Antidiarrheal Agents

  • Intestinal Adsorbents
    • Include Attapulgite, Activated charcoal, Kaolin, Pectin, Dioctahedral smectite
      • Few controlled studies of these agents in chronic diarrhea and results have been inconclusive
  • Bile Acid Sequestrant
    • Eg Cholestyramine
    • Effective for short-term treatment of diarrhea secondary to bile acid malabsorption 

Nonspecific Agents for Diarrhea

Bulk-Producing Laxatives

  • Eg Psyllium
    • Psyllium may alter stool consistency, changing watery stools to semi-formed ones


  • An alpha-adrenergic agonist, decreases gut motility and intestinal transport
  • Antihypertensive effect limits its use in most patients but could be useful in diabetics


  • A somatostatin analogue, may improve endocrine diarrhea, dumping syndrome and AIDS diarrhea
  • Usually considered a 2nd-line agent compared to opiates because of its administration by injection and cost


  • May stimulate local immunity by modifying colonic flora and may be useful for antibiotic-associated diarrhea

Other Empiric Therapies

Pancreatic Enzyme Supplementation

  • A therapeutic trial of supplementation is occasionally given in patients suspected of having pancreatic exocrine insufficiency

Conjugated Bile Acid Supplementation

  • Reduction of steatorrhea through empiric supplementation may be used to confirm the diagnosis of bile acid deficiency

Non-Pharmacological Therapy

  • Administer fluids and electrolytes to maintain hydration
    • Please see Diarrhea in Adults - Infectious Management Chart for specific therapy
  • Cereal-based solutions increase salt and water absorption but diarrhea may worsen with their use
    • Can be lifesaving in dehydrating acute secretory diarrheas (eg cholera) but use in chronic diarrhea has not been well studied

Specific Therapy

  • Institute specific therapy once the cause of chronic diarrhea is established
  • Please see the following Disease Management Charts:
    • Clostridium difficile Infection
    • Diarrhea in Adults - Infectious
    • Inflammatory Bowel Disease (IBD)
    • Irritable Bowel Syndrome (IBS)
    • Pancreatitis - Chronic
    • Parasitic Infections
    • Primary Biliary Cirrhosis
    • Zollinger-Ellison Syndrome
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