Endoscopic Evaluation of the Incidence and Etiology of Lower Gastrointestinal Bleeding in Patients Presenting With Melena

Although tarry stool is a common feature of peptic ulcer bleeding, it can also be a manifestation of lower gastrointestinal (GI) bleeding. Examples include colonic cancer, small bowel tumors, and small or large bowel ulcers induced by aspirin or painkillers (NSAIDs). However, clinicians are often misled by the finding of peptic ulcers as the source of GI bleeding. It is not uncommon to detect peptic ulcers incidentally but the source of bleeding is actually in the lower GI tract (e.g. NSAID- or aspirin-induced small or large bowel bleeding ulcers, small bowel tumors, or colorectal cancer). Delay in diagnosis of lower GI bleeding often leads to serious consequences.

The preferred investigations for lower GI bleeding are colonoscopy plus video capsule endoscopy. Colonoscopy has been the gold standard for the diagnosis of colonic bleeding. The risk of colonoscopy-induced complications such as bleeding or perforation is less than 1 in 3500. Video capsule endoscopy is a non-invasive, safe and accurate technology that has been approved by the FDA for investigation of small bowel diseases. The video capsule is an 11x 26mm capsule that encases a digital camera, light-emitting diodes, batteries, and a transmitter. The patient needs to swallow the video capsule after an overnight fast and wear a recording device for eight hours. Images are taken twice-per-second and transmitted to the recording device. Oral feeding can be resumed after four hours. There is no restriction to daily activities. The swallowed capsule will be expelled naturally after 5 to 12 hours virtually in all patients. The risk of capsule retention is very low and only occurs in patients with severe small bowel stricture.

This study aims to assess the incidence and etiology of lower GI bleeding in patients presenting with tarry stool. The result will provide important information about the magnitude of the problem of lower GI bleeding that will improve our patient care.