Risk Factors for Crohn's Disease of the Neo-Small Intestine in Ulcerative Colitis Patients with Total Proctocolectomy and Primary or Secondary Ileostomies

Background: De novo Crohn's disease (CD) of the neo-small intestine in ulcerative colitis (UC) patients after total proctocolectomy (TPC) is a new disease entity, which may persist even after a secondary diverting permanent ileostomy for pouch failure. We sought to compare outcomes of primary ileostomy (PI, i.e. stoma created after colectomy without trying of ileal pouch) and secondary ileostomy (SI, i.e. stoma created after pouch failure) and to evaluate factors associated with the development of CD of the neo-small intestine proximal to ileostomy. Methods: A total of 123 eligible patients were identified from our Pouch Center Registry (PI group, n = 57 and SI group, n = 66). Demographics, clinical features and outcomes (CD of the neo-small intestine, non-CD related strictures, requirement of CD-related medications use, ileostomy-associated hospitalization, ileostomy failure with stoma revision/relocation, and short-gut syndrome) were compared. Step-wise logistic regression models were performed. Results: The median follow-up for the whole cohort was 5.0 (2.0-12.0) years. Younger age at diagnosis and surgery, family history of IBD, toxic megacolon/fulminant colitis, pre-diversion severe diarrhea, pre-diversion anti-TNF biological therapy, arthralgia/arthropathy and staged surgery were more common in the SI group (p < 0.05). In multivariate analysis, the presence of SI [odds ratio (OR), 8.23; 95% confidence interval (CI), 2.43-27.85], family history of IBD (OR, 9.14; 95% CI, 3.13-26.69), and pre-diversion of weight loss (OR, 3.72; 95% CI, 1.23-11.21) were contributing factors for developing CD of the neo-small intestine. Conclusions: CD of the neo-small intestine in stoma patients was associated with the presence of SI, family history of IBD, and pre-diversion poor nutrition status. Patients with secondary ileostomy due to pouch failure should be carefully monitored. Aggressive medical, endoscopic or surgical therapy may be needed in patients at risk, before permanent diversion.