Prepouch Ileitis After Ileal Pouch-anal Anastomosis: Patterns of Presentation and Risk Factors for Failure of Treatment

Background and Aims: There is a lack in the literature about prepouch ileitis [PI], in particular regarding risk factors associated with failure of the medical treatment. Aim of the study is to analyse the characteristics of PI patients and to compare those who required surgery with those who were successfully treated with conservative therapy. Methods: All cases presenting a diagnosis of PI were included and analysed. Patients eventually requiring surgery were compared with those who were managed conservatively, for symptoms of presentation, endoscopic characteristics, and rate of response to medical treatment. A sub-analysis of outcomes based on the final histology was performed. Results: The overall incidence of PI among 1286 patients was 4.4% [57], after a median of 6.8 years from pouch surgery. Symptoms included increased frequency [26.4%], outlet obstruction [21%], and bleeding [15.8%]. Afferent limb stenosis affected 49.1% of patients. The comparison showed that patients requiring surgery had a higher rate of Crohn's disease and indeterminate colitis [42.1 vs 0% and 15.8 vs 2.6%, p < 0.0001], outlet obstruction as main symptom [47.4 vs 7.9%, p = 0.0023], and afferent limb stenosis [73.7 vs 36.8%, p = 0.008] at endoscopy. Rate of failure of medical treatment at 5 years was 8.2% in patients with ulcerative colitis and 75% in the presence of both indeterminate colitis and Crohn's disease [p < 0.0001]. Conclusions: Crohn's disease, indeterminate colitis, and stenosis with outlet obstruction are risk factors for failure of treatment