How to manage diarrhea after an ileostomy reversal?

Management of Diarrhea After Ileostomy Reversal

Start with loperamide 4 mg four times daily as first-line therapy, escalating to 12-24 mg per dose if needed, combined with dietary modifications to thicken stool output. 1, 2, 3

Immediate Pharmacologic Intervention

Loperamide is the cornerstone of treatment and should be initiated immediately, as it reduces water and sodium output by 20-30%. 1, 2 The FDA specifically indicates loperamide for reducing ileostomy discharge volume. 3

• Dosing strategy: Begin with 2-4 mg taken 30 minutes before each meal (4 times daily). 1
• Dose escalation: If inadequate response, increase to 12-24 mg per dose due to disrupted enterohepatic circulation after intestinal surgery. 1, 2
• Loperamide is superior to codeine phosphate (60 mg four times daily) because it is non-sedating, non-addictive, and does not cause fat malabsorption. 1

If loperamide alone fails after 1-2 weeks, add codeine phosphate 30-60 mg taken 30 minutes before meals. 1

Dietary Management to Thicken Output

Implement specific bulking foods immediately to reduce stool frequency and volume:

• Thickening agents: Bananas, pasta, rice, white bread, mashed potatoes, marshmallows, or jelly. 1, 2
• Reduce fiber intake: High fiber increases loose stools, flatulence, and bloating. 1
• Avoid obstruction risks: Chew food thoroughly and limit fruit/vegetable skins, sweetcorn, celery, and whole nuts (smooth nut butters are acceptable). 1
• Small frequent meals: 4-6 nutrient-dense meals daily rather than large portions. 1

Fluid and Electrolyte Management

Fluid management is critical but counterintuitive—excessive hypotonic fluids paradoxically worsen diarrhea and dehydration:

• Target 2-2.5 liters daily, increased during hot weather or exercise. 1, 2
• Avoid hypotonic fluids (tea, water) and hypertonic drinks (fruit juice) as these increase stoma output and worsen dehydration. 1, 2
• Prioritize isotonic drinks: Sports drinks or oral rehydration solutions (Dioralyte). 1
• Homemade rehydration solution: 1 liter water with 6 teaspoons glucose, 1 teaspoon salt, ½ teaspoon sodium bicarbonate or citrate. 1
• Monitor urinary sodium to detect occult dehydration. 1

Add extra salt to meals (0.5-1 teaspoon daily) to prevent sodium depletion. 1

Bile Acid Malabsorption Treatment

Bile acid malabsorption occurs in over 80% of patients after ileal resection and is a primary cause of post-reversal diarrhea. 2

• Initiate a therapeutic trial of cholestyramine (bile acid sequestrant) if diarrhea persists despite loperamide and dietary changes. 1, 2
• Caution: Cholestyramine further reduces the bile salt pool and may worsen fat malabsorption, so use only when bile acid diarrhea is suspected (typically with >100 cm terminal ileum resected). 1

Gastric Acid Suppression for High-Volume Diarrhea

For persistent high-volume diarrhea exceeding 2 liters daily, add gastric acid suppression:

• Omeprazole 40 mg once daily (oral or IV if <50 cm jejunum remains). 1, 2
• Alternative: Ranitidine 300 mg twice daily or cimetidine 400 mg four times daily. 1, 2
• These agents reduce jejunostomy output particularly in patients with net secretory output. 1

Rule Out Specific Causes

Investigate these conditions if diarrhea persists despite standard management:

• C. difficile colitis: Especially if extremely watery diarrhea, foul flatus, and abdominal cramping. 1, 2, 4
• Small intestinal bacterial overgrowth (SIBO): Affects 30% of patients after intestinal resection; treat empirically with rifaximin for 2 weeks. 1, 2
• Recurrent Crohn's disease: If inflammatory bowel disease was the original indication. 1, 2
• Anastomotic stricture or obstruction: Structural complications must be excluded. 1, 2
• Lactose intolerance: Consider lactose-free diet trial. 1

Monitoring Requirements

• Serum potassium: Supplement with potassium-rich foods (bananas, potatoes, spinach, fish, poultry, sweet potato, avocado) if levels are low. 1
• Vitamin B12: Monitor regularly as terminal ileum resection impairs absorption. 1
• Urinary sodium: Check to detect dehydration. 1

When to Escalate Care

Consider parenteral fluid and electrolyte infusions if oral management fails to maintain hydration despite optimized dietary and pharmacologic interventions. 1, 2 This typically requires 0.5-1 liter saline subcutaneously 1-3 times weekly or IV if needed more frequently. 1