Background and aim: Diarrhea and urgency is a debilitating long term complication of ileal pouch anal anastomosis (IPAA) after a proctocolectomy. Somatostatin analogues are used to control diarrhea and high output ostomies. Hence, we designed a prospective, double blind, cross-over trial to explore the efficacy and tolerability of octreotide to reduce diarrhea in adult patients with IPAA. Methods: Patients were randomized to octreotide SC 500 μg tid or matching placebo SC for 7 days. Responders (reduction in stool frequency of ≥3 and ≥30%, primary endpoint) remained in the same group and non-responders could cross over to the alternative treatment for 7 days. Open label octeotide LAR 30 mg was offered to all responders on day 14. Flexible pouchoscopy with biopsies was performed at baseline in all patients and repeated on day 7, 14 in patients with pouchitis. Results: Fifteen patients (11 male, median age 52 yrs), all UC, were randomized. Three patients were withdrawn for side effects during the blinded phase. Response was reached by 2/12 and 2/11patients treated with octreotide or placebo respectively (including cross-over, p=0.9). Median stool frequency remained stable in both groups [Δoctreotide: 0 (IQR -4 to 0), ΔPlacebo: -1 (IQR -1 to 1), p=0.45]. Octreotide had no effect on the Modified pouch disease activity index (mPDAI) and pouchitis persisted in 5/6 subjects with pouchitis at onset. One received open label octreotide LAR. Conclusion: Octreotide has no clear beneficial effect on the stool pattern nor on pouchitis severity in patients with high stool frequency after IPAA.