Of all patients, 61.5% experienced worse postoperative QoL, with significantly lower QoL level than that of an age and sex-standardized general population in 12 dimensions of the 15D-instrument, with the highest mean difference QoL scores calculated for excretion, sexual activity and sleeping dimensions. Older age and preoperative hypertension were the only significant predictors of lower overall QoL (p = .003 and p = .03, respectively). A preoperative age of ≥35 years was the most valid predictor of lower postoperative QoL (Sensitivity = 62.4% and Specificity = 49.6%, p = .04). In conclusion, postoperative QoL is generally low using the 15D-instrument after IPAA. Worse postoperative QoL is predicted after the age of 35.