Pre-IPAA antibiotics & pouchitis

Pre-IPAA antibiotics & pouchitis

May 13, 2024

Issue 10

Clinical Question

Does antibiotic use in the year before IPAA increase risk of pouchitis?

Editor’s Bottom Line

Use of antibiotics prior to ileal-pouch anastomosis for ulcerative colitis is associated with an increased risk of subsequent pouchitis. This observation provides further evidence suggesting a microbial etiology for pouchitis.


Barnes EL, Karachalia Sandri A, Herfarth HH, Jess T. Antibiotic Use in the 12 months Prior to Ileal Pouch-Anal Anastomosis Increases the Risk for Pouchitis. Clin Gastroenterol Hepatol. Epub ahead of print March 29, 2024;


American and Danish researchers examined risk factors for pouchitis in the two years following ileal pouch-anal anastomosis (IPAA) using data from 1,616 adults with ulcerative colitis who were registered in a prospective Danish national registry and had undergone IPAA between 1996 and 2020.

Patients in the study were a mean 36 years of age at the time of IPAA, and 55% were male. Fifty-one percent had been prescribed antibiotics in the year prior to the final stage of IPAA. Forty-six percent of all patients developed pouchitis in the first two years after IPAA.

Multivariate analysis adjusting for a range of variables found that those who received antibiotics in the 12 months prior to the final stage of IPAA were 41% more likely to experience pouchitis in the two years after IPAA (adjusted Hazard Ratio [aHR]: 1.41; 95% Confidence Interval [CI], 1.22–1.64; p<0.001), compared to those who did not receive antibiotics.

Parsing the data by the number of prescriptions, those with one or two antibiotic prescriptions in the year pre-IPAA had a 30% higher risk of pouchitis (aHR: 1.30; 95% CI, 1.11–1.52; p<0.05) and those with three or more courses of antibiotics had a 77% higher risk (aHR: 1.77; 95% CI, 1.41–2.21; p<0.05), compared to those who did not receive antibiotic prescriptions.

The risk of pouchitis in the two years after IPAA remained significant after the authors excluded patients who received antibiotics in the 30 days prior to the final stage of IPAA (aHR: 1.28; 95% CI, 1.11–1.48; p<0.05). The relationship was also significant when including only those prescribed an antibiotic between the time of colectomy and the final stage of the IPAA (aHR: 1.31; 95% CI, 1.12–1.52; p<0.05).

Anti-tumor necrosis factor (TNF) use in the year prior to IPAA was also associated with a higher risk of pouchitis (aHR: 1.53; 95% CI, 1.32–1.78; p<0.05).

Use of non-steroidal anti-inflammatory drugs in the 12 months before the final stage of IPAA did not impact pouchitis risk in the two years after IPAA.

Appendectomy in the year prior to the final stage of IPAA did not increase the risk of pouchitis.


Study Design: Population-based cohort
Funding: The American Gastroenterological Association, the National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health, and the Danish National Research Foundation.
Allocation: Not applicable
Setting: Multicenter
Level of Evidence: 2b