Colonoscopy in patients aged 80 years or older and its contribution to the evaluation of rectal bleeding

Colonoscopies performed in patients aged 80 years or older at the Sheba Medical Center were analysed according to the primary indication for the procedure: 101 colonoscopies were performed because of rectal bleeding of at least 2 months duration, and 335 for all other indications. Carcinoma of the large bowel was found in 29 (28.7%) bleeders, with the rectum being the most frequently involved site (12 patients). Among the non-bleeders, the prevalence of cancer was significantly lower (33 cases, 9.8%; P less than 0.001), and rectal carcinoma was less common (five patients, P = 0.04), but proximal tumours were more frequent. Of patients with cancer who had operations, the majority (72%) had a tumour confined to the bowel wall (Dukes A or B). The rate of adenomas was similar for both groups (34% vs 29%). The non-bleeders complained more frequently of abdominal pain or a change in bowel habits as compared to the bleeders, but both groups had similar rates for anaemia and weight loss. In all, 47% of these octogenarians with cancer, and 26% with adenomas were referred for colonoscopy because of rectal bleeding. This procedure was found to be safe in old age, as we recorded only four (0.9%) non-fatal complications among our series, a similar figure to the overall incidence of complications at our Institute. In conclusion, our data indicate that rectal bleeding in octogenarians warrants a complete colonic investigation, preferably by total colonoscopy.