What is the treatment approach for chronic diarrhea?

Treatment Approach for Chronic Diarrhea

The first-line treatment for chronic diarrhea is loperamide, which should be initiated at a dose of 4 mg followed by 2 mg every 2-4 hours or after each unformed stool, with a maximum daily dose of 16 mg. 1, 2

Initial Assessment and Classification

• Chronic diarrhea is defined as abnormal passage of ≥3 loose stools per day for more than 4 weeks 3, 1
• Initial screening should include full blood count, ferritin, tissue transglutaminase/EMA, thyroid function test, and fecal calprotectin to identify underlying causes 3, 1
• Stool tests for inflammation and infectious causes should be performed to rule out treatable conditions 3
• Bristol stool chart is recommended for assessment—type 5 and above indicates diarrhea 3

Treatment Algorithm

First-Line Pharmacological Treatment

• Loperamide is FDA-approved for chronic diarrhea in adults and is the drug of choice 1, 2
• Maintain adequate fluid intake as indicated by thirst; drinks containing glucose or electrolyte-rich soups are recommended 3
• Dietary modifications should be tailored to the underlying cause, including:
  • Avoiding spices, coffee, alcohol, and reducing insoluble fiber 1
  • Following a bland/BRAT (bread, rice, applesauce, toast) diet may be helpful 1
  • Small, light meals guided by appetite; avoid fatty, heavy, spicy foods 3
  • Consider avoiding lactose-containing foods in prolonged episodes 3

Second-Line and Cause-Specific Treatments

• If loperamide is ineffective, other opioids such as tincture of opium, morphine, or codeine may be considered 1, 4
• For bile acid malabsorption-related diarrhea, bile acid sequestrants like cholestyramine are beneficial 1, 5
• For inflammatory diarrhea, budesonide 9 mg once daily may be effective in refractory cases 1
• For functional disorders (IBS-D), additional approaches include:
  • 5-HT3 receptor antagonists 5
  • Low-dose tricyclic antidepressants 5
  • The antibiotic rifaximin 5
  • Low-FODMAP diet 5, 6

Special Considerations

• Monitor for electrolyte imbalances, particularly hypokalemia, especially with large-volume diarrhea 1
• Rehydration (oral or parenteral) is essential for patients with large-volume diarrhea 1
• Patients should seek medical advice if:
  • No improvement is seen in 48 hours 3
  • Symptoms worsen or overall condition deteriorates 3
  • Warning signs develop (severe vomiting, dehydration, persistent fever, abdominal distension, or blood in stools) 3

Common Pitfalls and Caveats

• Loperamide overdose can cause serious cardiac adverse reactions, including QT/QTc interval prolongation and arrhythmias 1
• Empiric antimicrobial use for all diarrheal episodes is not recommended due to increasing drug resistance 1
• Chronic use of stimulant laxatives for constipation can cause diarrhea and hypokalemia 1
• Functional disorders such as irritable bowel syndrome are common causes of chronic diarrhea but should be diagnosed only after excluding organic causes 7
• Dietary treatments should balance symptom improvement without compromising nutritional health 6