Introduction:Permanent ileostomy is required at times in patients suffering from chronic inflammatory bowel disease or following complications after treatment of colorectal cancer. While a stoma may adversely affect patients' quality of life (QOL), little is known about the fate of these patients in the long-term. The aim of this study was to characterize long-term QOL in ileostomy patients and identify factors associated with deteriorated QOL.Patients and Methods:1434 ileostomy patients (40% male) were identified in the database of a German self-help organization for stoma patients (ILCO e.V.). A standardized questionnaire including the Short Form 36 (SF-36), the Cleveland Global Quality of Life Instrument (CGQL), and the Gastrointestinal Quality of Life Index (GIQLI) were mailed to these patients. 783 patients (55%) responded to the survey (age 57 years [24-94 y] (median [range]); 41% male). Subgroup analysis for patients with/without small bowel resection or stoma-related problems was performed. QOL data are expressed as % of maximum score with 100 being best QOL (mean±SEM).Results:Median follow-up after diversion was 14 years [1-51 y]. Underlying disease was ulcerative colitis in 344 patients (44%), Crohn's disease in 300 patients (38%), malignancy in 51 patients (7%), familial adenomatous polyposis in 48 patients (6%), and others in 40 patients (5%). 238 patients (30%) reported to have undergone resection of small intestine which did not have any effect on QOL on the different subscales of the applied QOL instruments. 138 patients reported on daily stoma output which was 1347±71 ml (mean±SEM) and 80 patients (10%) stated to suffer from short bowel syndrome. 492 patients (63%) indicated a total of 857 stoma-related problems: skin irritation 34%, intermittend blockade of feces 16%, hernia 13%, stenosis 11%, retraction 10%, prolapse 8%, others 8%. Presence of stoma-related problems was associated with deteriorated QOL on all subscales (p<0.003) except on the subscale social functioning of the SF-36 (problem: 47±1% vs no problem: 46±1%; p=0.7) with a mean difference in QOL of 9±1%. The type of ileostomy also affected QOL with end-ileostomy and Kock-Pouch showing a better QOL compared to loop-ileostomy on most subscales.Conclusions:While small bowel resection appears not to have any effect on QOL, stoma-related problems which were frequently reported seem to deteriorate QOL substantially. It, therefore, appears of paramount importance to avoid stoma related problems in order to achieve good QOL when permanent ileostomy is necessary.