PURPOSE: Although functional results after ileal pouch-anal anastomosis are excellent, imperfections of function do occur. In this setting, quality-of-life assessment is an invaluable tool in determining overall therapeutic efficacy. We evaluated the impact of dietary restrictions, preoperative diagnosis (ulcerative colitis vs. familial adenomatous polyposis), and pregnancy (after pouch insertion) on quality of life. METHODS: After ethical approval, 64 patients were reviewed (mean age, 31 (range, 15-54) years). Long-term quality of life in patients after ileal pouch-anal anastomosis was assessed using the Cleveland Global Quality of Life instrument or Fazio score. The Cleveland Global Quality of Life score is a novel quality-of-life instrument specifically designed for patients with ileal pouches. Stool frequency and continence were recorded to establish the functional status of this group. RESULTS: Sixty-one patients (95.3 percent) complained of some form of dietary restriction and adopted a fixed dietary regimen. All such patients felt that a breach of this regimen would impinge significantly on their quality of life. Late eating and alcohol were associated with diarrhea, whereas smoking was not. Constipation was infrequently reported. The mean Cleveland Global Quality of Life score of patients with ulcerative colitis (0.81 +/- 0.13) was greater than that of patients with ulcerative colitis and a background of pouchitis (0.78 +/- 0.16; P = 0.042). Whereas postoperative stool frequency in patients with familial adenomatous polyposis was always higher than the preoperative level (4 vs. 2 movements per day; P = 0.04), the Cleveland Global Quality of Life score of this group was lower than that of ulcerative colitis patients (0.77 vs. 0.81; P = 0.047). The Cleveland Global Quality of Life score of females who had had pregnancies after pouch formation was 0.70, significantly lower (P = 0.039) than that of ulcerative colitis patients, although pouch function was similar to the general group (7 vs. 6 daily bowel movements with full continence in all parous patients). CONCLUSIONS: Most patients suffered dietary restrictions, forcing them to adopt a fixed dietary regimen. Breach of this regimen would impact on their quality of life. Hence composition of diet and timing of intake are important determinants of quality of life after ileal pouch formation. Patients with familial adenomatous polyposis and those with a history of pouchitis had poorer Cleveland Global Quality of Life scores than ulcerative colitis patients without a background of pouchitis. This indicates that they also had poorer quality of life. Parous patients had the lowest Cleveland Global Quality of Life scores, indicating the poorest quality of life. These differences did not correlate with poorer pouch function, highlighting the influence of non-pouch-related factors in quality of life after ileal Pouch formation.