BACKGROUND: Pouchitis is the most common complication after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis. Induction and maintenance of remission is a crucial therapeutic goal. We investigated curcumin's efficacy in treatment of pouchitis. METHODS: The double-blind trial included an induction cohort of refractory pouchitis patients and a maintenance cohort of patients without pouchitis after IPAA. Patients received either placebo or curcumin for 8 weeks. The pouchitis activity were assessed before and after and was compared between cohorts or groups. Laboratory inflammation indicators, nutritional status and quality of life were also appraised. RESULTS: 52 patients were included, with 39 and 13 patients entering the maintenance cohort and induction cohort, respectively. In maintenance cohort, the proportion of clinical remission elevated from 11 to 89% in curcumin group (p = 0.005), whereas there was no significant difference in placebo group (10% vs 5%, p = 1).In induction cohort, 67% (4/6) patients achieved clinical response after 8 weeks' intervention of curcumin, whereas none treated with placebo (p = 0.021). Patients treated with curcumin appeared less inflammation and there was no significant difference in indicators changes between two cohorts. CONCLUSIONS: Curcumin has preventive and therapeutic effects on pouchitis. Curcumin supplementation can reduce the disease activity and improve the nutritional status of patients with after IPAA. TRIAL REGISTRATION: ChiCTR, ChiCTR1900022243. Registered 31 March 2019, https://www.chictr.org.cn/historyversionpub.aspx?regno=ChiCTR1900022243.