Loop ileostomy is widely employed after low rectal anastomosis to prevent pelvic sepsis from anastomotic leakage. However, stoma closure carries a risk of morbidity and even mortality in some cases. It is important to assess complications after stoma closure for maximizing the benefit of making loop ileostomy. The aim of this study was to review and examine the possible risk factors associated with complications after closure of loop ileostomies. A retrospective analysis, which focused on risk factors for complications after surgery, was performed for 82 consecutive patients who underwent elective closure of loop ileostomy from 2005-2012 at Hiroshima University Hospital. Postoperative complications developed in 22 patients (26.8%): 12 (14.6%) had an ileus, 8 (9.8%) had a wound infection, 2 (2.4%) had an intraperitoneal abscess and 1 had pseudomembranous enterocolitis. There was no postoperative mortality. In univariate analysis, gender and higher body mass index (BMI) were identified as significant risk factors for postoperative complications. After multivariate analysis, a BMI of 24 kg/m2 was identified as the cut-off value, above which significantly higher incidences of postoperative complications were observed. Furthermore, patients who succeeded in reducing their weight (BMI <24 kg/m2) between the first and second surgeries had less morbidity than patients who remained obese (BMI >24 kg/m2). Our study showed that the majority of complications associated with ileostomy closure are ileus. A BMI >24 kg/m2 is an independent risk factor for postoperative complications. Weight loss programs before stoma closure might reduce postoperative complications.