What is the treatment approach for diversion colitis following ileostomy reversal?

Treatment of Diversion Colitis Following Ileostomy Reversal

The definitive treatment for diversion colitis is restoration of intestinal continuity through ileostomy reversal, which resolves the inflammation in nearly all cases by reestablishing the fecal stream to the previously diverted colon. 1, 2

Understanding the Condition

Diversion colitis develops in the defunctioned colonic segment after fecal diversion, occurring in nearly all patients with a diverted bowel, though most remain asymptomatic 1. The pathophysiology involves:

• Depletion of short-chain fatty acids (SCFAs) from lack of luminal bacterial fermentation 1, 3
• Altered microbiome with increased aerobic bacteria 3
• Immune dysregulation in the diverted segment 3

Primary Treatment Strategy

Surgical Restoration (First-Line)

Ileostomy reversal with restoration of bowel continuity is the only curative intervention and should be pursued whenever feasible 1. This approach:

• Resolves inflammation by reestablishing the fecal stream 1
• Provides definitive cure rather than temporary symptom control 2
• Should be performed electively after patient optimization 4

Medical Management (For Non-Surgical Candidates)

When ileostomy reversal is not immediately feasible or contraindicated, pharmacologic treatments include:

Short-chain fatty acid (SCFA) enemas are the most physiologically targeted therapy, directly replacing the deficient metabolites 1, 3. Administer as retention enemas to the diverted segment.

5-aminosalicylic acid (mesalamine) enemas have demonstrated efficacy in reducing mucosal inflammation 1, 3. Standard dosing is 1 gram daily via enema to the rectal stump 5.

Corticosteroid enemas can be used for more severe inflammation 1, 3. Prednisolone sodium phosphate 20 mg enemas are typically administered 5.

Combined therapy may be superior to monotherapy. A combined mesalamine 1 gram plus prednisolone sodium phosphate 20 mg enema administered once daily showed improved efficacy in patients with refractory diversion colitis associated with inflammatory bowel disease 5.

Emerging Therapies

Fecal microbiota transplantation (FMT) represents a promising treatment option that addresses the underlying microbiome dysbiosis 3. FMT offers:

• Low medical costs and ease of administration 3
• Minimal side effects 3
• Potential for prophylactic use to prevent postoperative diversion colitis 3

Probiotics have shown benefit in recent reports, though evidence remains limited 3.

Special Considerations for IBD Patients

In patients with underlying inflammatory bowel disease who develop diversion colitis:

• Differentiation between diversion colitis and underlying IBD activity can be challenging 2
• Close endoscopic surveillance is mandatory, as cancer risk in the rectal stump reaches 4.5 per 1,000 diverted patient-years in IBD patients with prior dysplasia or cancer 2
• Patients should be counseled for definitive surgery with or without restoration of intestinal continuity 2
• Success rates for stoma reversal in Crohn's disease with perianal involvement are particularly low (only 17% achieve successful reversal) 6

Clinical Algorithm

1. Assess surgical candidacy: Evaluate patient for ileostomy reversal feasibility based on nutritional status, inflammatory markers, and underlying disease activity 4

2. If reversal is appropriate: Proceed with elective laparoscopic restoration of continuity after optimizing nutrition and reducing steroid dependence 4

3. If reversal is contraindicated or delayed: Initiate combined mesalamine (1 gram) plus corticosteroid (prednisolone 20 mg) enemas once daily 5

4. If medical therapy fails: Consider FMT as an alternative approach targeting microbiome restoration 3

5. For IBD patients: Implement endoscopic surveillance protocol and reassess for definitive proctectomy if inflammation persists or dysplasia develops 2

Critical Pitfalls to Avoid

• Do not delay ileostomy reversal indefinitely in surgical candidates, as prolonged diversion increases cancer risk in IBD patients 2
• Do not use systemic corticosteroids when topical therapy can be delivered directly to the affected segment 5
• Do not assume symptomatic improvement equals mucosal healing; endoscopic assessment is necessary 5
• Do not overlook the possibility of recurrent underlying IBD versus diversion colitis in patients with inflammatory bowel disease 2