Risk Factors and Management of Incomplete Microscopic Colitis: A Systematic Review and Meta-Analysis.

Area of Science:

• Gastroenterology
• Colorectal Diseases
• Inflammatory Bowel Disease

Background:

• Incomplete microscopic colitis (MCi) describes patients with chronic watery diarrhea not meeting full microscopic colitis (MC) criteria.
• Epidemiology and optimal management of MCi remain inconsistently defined.

Purpose of the Study:

• To systematically review and pool data on the epidemiology, patient characteristics, risk factors, and treatment outcomes for incomplete microscopic colitis (MCi).
• To evaluate the clinical response and relapse rates following treatment for MCi.

Main Methods:

• Systematic search of RCTs and observational studies (Cochrane, Medline, Scopus, Embase) for adults with biopsy-proven MCi.
• Data extraction on incidence, prevalence, patient features, risk factors, treatment response, and relapse.
• Random-effects model used for data pooling to calculate weighted estimates and 95% CIs.

Main Results:

• 17 studies (1 RCT, 16 observational) including 1370 MCi patients (median age 62, 69.6% women) were analyzed.
• MCi incidence ranged from 0.96 to 5.0 cases per 100,000 person-years.
• Pooled remission rate was 78% with any induction therapy and 85% with budesonide.

Conclusions:

• MCi patients share demographic, risk factor, and treatment response characteristics with complete MC.
• Findings suggest that current histologic criteria for MC may need broadening to include MCi.
• High remission rates with budesonide indicate its efficacy in managing MCi.