Construction of a gastrointestinal stoma is a frequently performed surgical procedure. We sought to analyze a large cohort to document the frequency and types of ostomy complications and the risk factors associated with them. The charts of patients undergoing a procedure which resulted in ostomy during a 3-year period were reviewed. Demographics, indication, ostomy type/location, perioperative risk factors, and complications were recorded. Case-control methodology was used to determine crude odds ratios and multiple logistic regression was used to calculate adjusted odds ratios. A P value of less than 0.05 was considered significant. An ostomy was constructed in 204 patients and records were available for 164. Forty-one patients (25.0%) had ostomy complications. Sixteen of these complications (39.0%) occurred within one month of the procedure. Complications included prolapse in nine (22%), necrosis in nine (22%), stenosis in seven (17%), irritation in seven (17%), infection in six (15%), bleeding in two (5%), and retraction in two (5%). Gender, cancer, trauma, diverticulitis, emergency surgery, ileostomy, and ostomy location/type were not associated with a stoma complication. Significant predictors of ostomy malfunction are presented as odds ratios (ORs) with 95 per cent confidence intervals (CIs) and include inflammatory bowel disease (OR = 4.49; 95% CI = 1.16-17.36) and obesity (OR = 2.66; 95% CI = 1.15-6.16). The care of an enterostomal nurse was found to prevent complications (OR = 0.15; 95% CI = 0.03-0.69). We conclude that ostomies have a high risk of complication, which is not related to stoma location or type. Obesity and inflammatory bowel disease predispose to complications. Enterostomal nursing may be instrumental in preventing complications.