Relationship between endoscopic findings of the pouch and bowel frequency after restorative proctocolectomy in ulcerative colitis

Abstract

Background and aim: Pouchitis is one of the late complications of restorative proctocolectomy in ulcerative colitis (UC) and is associated with increased bowel frequency. The present study aimed to clarify the endoscopic findings that are associated with bowel frequency. Patients and methods: The macroscopic and microscopic features in the ileum proximal to the pouch, the pouch, and the remnant short rectum in 100 endoscopies on 63 patients were studied retrospectively. Results: Four of 28 (14%) patients had inflammatory changes in the proximal ileum. Sixty-seven percent of patients showed an abnormal appearance of the pouch. Granularity, friability, presence of mucus, erythema, and erosions were significantly related to bowel frequency. ‘Endoscopic pouch activity index’ (EPAI), which is the number of positive findings of diffuse erythema, mucus, friability, ulcer, erosion, and granularity, was strongly associated with bowel frequency (P < 0.0001). Patients without macroscopic inflammation in the rectum had significantly lower bowel frequency than those with mild or moderately active inflammation (P = 0.0294 and 0.0183, respectively). Multivariate analysis revealed that ‘endoscopic pouch activity index’ and histological grade of pouch inflammation were significant factors (P = 0.0004 and P = 0.0429, respectively) influencing bowel frequency. Time–course study demonstrated that changes in EPAI and macroscopic grade of the rectum were significantly related to alteration in bowel frequency (P = 0.0120 and 0.0244, respectively). Conclusion: Erythema, mucus discharge and granularity were significantly related to bowel frequency. EPAI may be useful to evaluate endoscopic pouch inflammation.