What are the treatment recommendations for chronic diarrhea?

Treatment Recommendations for Chronic Diarrhea

A systematic diagnostic approach followed by targeted treatment is essential for managing chronic diarrhea effectively, with specific therapies directed at the underlying cause rather than just symptom control. 1

Initial Diagnostic Workup

First-line Investigations

• Blood tests: Full blood count, ferritin, tissue transglutaminase antibodies (for celiac disease), thyroid function tests 1, 2
• Stool tests:
  • Fecal calprotectin (to exclude inflammation, particularly important in patients under 40 with suspected IBS) 1
  • Fecal immunochemical testing (FIT) for patients with lower GI symptoms without rectal bleeding 1

Secondary Investigations (Based on Initial Results)

• Colonoscopy with biopsies of right and left colon (not rectal) for:
  • Patients with altered bowel habits and/or rectal bleeding 1
  • Patients over 45 years old 1
  • To exclude microscopic colitis 1, 2
• Bile acid malabsorption testing: SeHCAT testing or serum bile acid precursor 7α-hydroxy-4-cholesten-3-one 1, 2
• Small bowel imaging: MR enterography or video capsule endoscopy if small bowel pathology is suspected 1
• Pancreatic function: Fecal elastase testing when fat malabsorption is suspected 1, 2

Treatment Recommendations by Cause

1. Bile Acid Diarrhea

• Treatment: Cholestyramine 2
• Note: Making a positive diagnosis is preferred over empirical treatment 1

2. Microscopic Colitis

• Treatment: Budesonide 2
• Diagnosis: Requires colonoscopy with biopsies of right and left colon 1

3. Celiac Disease

• Treatment: Strict gluten-free diet 2
• Diagnosis: Tissue transglutaminase antibodies and duodenal biopsies 1

4. Small Bowel Bacterial Overgrowth

• Treatment: Empirical trial of antibiotics 1, 2
• Note: Routine hydrogen/methane breath testing is not strongly recommended 1

5. Pancreatic Insufficiency

• Treatment: Pancreatic enzyme replacement therapy 2
• Diagnosis: Fecal elastase testing 1

6. Inflammatory Bowel Disease

• Treatment: Based on severity:
  • Mild-moderate: Mesalamine 2
  • Moderate-severe: Prednisolone 2
• Diagnosis: Colonoscopy with biopsies, fecal calprotectin 1

7. Functional/IBS-Diarrhea

• Treatment: Loperamide for symptomatic relief 2, 3
• Note: Loperamide provides more rapid control of symptoms than diphenoxylate and has a longer duration of effect 3

8. Lactose Intolerance

• Diagnosis: Hydrogen breath testing or trial of lactose withdrawal 1, 2
• Treatment: Dietary lactose restriction 1

Symptomatic Management

When specific cause treatment is ongoing or for symptomatic relief:

• First-line antidiarrheal: Loperamide 2, 3

  • Dosing: Can be used at 2-8 mg daily, titrated to effect 4, 5
  • Advantage: Longer duration of effect than alternatives, possibility of once-daily dosing in chronic diarrhea 3

• Dietary modifications:

  • Elimination of trigger foods 2
  • Reduction of FODMAPs (fermentable oligo-, di-, mono-saccharides and polyols) 1
  • Reduction of caffeine, alcohol 1

Common Pitfalls to Avoid

1. Missing bile acid diarrhea, which is common and underdiagnosed 2
2. Overlooking microscopic colitis, particularly in older patients with watery diarrhea 2
3. Failing to consider medication-induced diarrhea - always review all medications including OTC products 1, 2
4. Inadequate investigation of alarm symptoms such as weight loss, nocturnal symptoms, or blood in stool 1, 2
5. Using antidiarrheal agents in contraindicated situations such as in extremely ill patients, those with obstruction, colonic dilation, fever, or abdominal tenderness 6

Follow-up

• Reassess patients in 3-6 weeks to evaluate treatment effectiveness 2
• Monitor for alarm features that may indicate disease progression or complications 2
• Consider alternative diagnoses if initial treatment is ineffective 1

By following this systematic approach to diagnosis and treatment, most cases of chronic diarrhea can be effectively managed with significant improvement in patient outcomes and quality of life.