Aim Little is known about how ileal pouch‐anal anastomosis (IPAA) influences anorectal manometric data. This study aimed to clarify temporal changes in anorectal manometric data and faecal incontinence in IPAA. Methods We examined 32 patients with ulcerative colitis (UC) or familial adenomatous polyposis (FAP) undergoing restorative proctocolectomy with stapled or hand‐sewn IPAA. Maximum resting pressure (MRP) and maximum squeezing pressure (MSP) were analysed before and 1–3, 6–9, and 12–24 months after IPAA. Cleveland Clinic Florida‐Faecal Incontinence Score (CCF‐FIS) was measured 6–9 and 12–24 months after IPAA. Results Fourteen patients underwent stapled IPAA and 18 patients underwent hand‐sewn IPAA. MRP decreased 1–3 months after stapled IPAA (median: 42.3 mmHg vs. 60.0 mmHg at preoperative value, p = 0.039), but recovered afterwards. In hand‐sewn IPAA, the median MRP decreased to 29.5 mmHg at 1–3 months after IPAA (baseline: 64.8 mmHg, p < 0.0001), and remained unchanged thereafter. Stapled IPAA did not affect MSP; however, hand‐sewn IPAA caused a reduction in the median MSP from 191.3 mmHg to 141.3 mmHg at 1–3 months (p = 0.035), which gradually increased afterwards. The median CCFFIS was 5.5 points at 6–9 months and 2 points at 12–24 months after stapled IPAA. The score was high (11 points) at 6–9 months but decreased to 5 points at 12–24 months after hand‐sewn IPAA (p = 0.022). Conclusion We present time trends in functional outcomes of IPAA. MRP showed a transient decrease after stapled IPAA, whereas it remained low after hand‐sewn IPAA. CCFFIS was high only at 6–9 months after hand‐sewn IPAA.