What is the diagnostic yield of colonoscopy in patients with a referral diagnosis of constipation in South Africa?

Background: Constipation is a common problem for referral to surgical and colorectal units. Its association with colorectal cancer is controversial. Some authors have found an increased incidence while others have not. The aim of this study is to investigate the incidence of colorectal cancer (CRC) and other significant colonoscopic pathologies in patients undergoing colonoscopy for constipation. Methods: All colonoscopy reports for constipation were retrieved from our database from January 2011 to 30 June 2014. Data extracted included demographics, colonoscopic findings and adequacy of bowel preparation. Exclusion criteria included patients with other symptoms known to be associated with colonic neoplasia such as lower GIT bleeding, loss of weight, patients with associated anaemia, those with abnormalities on imaging, patients with personal or family history of colorectal cancers or colorectal polyps and patients with inflammatory bowel disease. The primary outcome was the presence of neoplasia at colonoscopy and the secondary outcomes were other colonoscopy findings. Results: A total of 985 colonoscopies were performed from January 2011 to June 2014 of which 144 were done for a referral diagnosis of constipation. Eighty eight (61.1%) were female. Their mean age was 58.6 + 13.8 years (range 19-95 years). There were 61 (42.4%) African patients, 38 (26.4%) White, 33 (22.9%) Asians and 12 (8.3%) Coloured patients. Eighty seven (60.4%) patients had a normal colonoscopy, 20 (13.9%) diverticular disease, 14 (9.7%) polyps of which 6 (4.2%) were neoplastic, and 9 (6.3%) had colorectal cancer. Conclusions: Constipation is associated with CRC. The presence of constipation should be a criterion for colonoscopy regardless of age or any other associated clinical features.