[Mysterious lower gastrointestinal bleeding in diverticular disease of the colon]

Within a few weeks a 78-year-old woman presented three times in hospital with dramatic blood loss in need of transfusion. At her admission to hospital she complained about general weakness and painless melena. Within the last few years the patient had been treated with aspirin and phenprocoumon for chronic atrial fibrillation and coronary heart disease.

Laboratory findings revealed a very low hemoglobin of 6 g/dl when the patient presented at hospital. The esophagogastroduodenoscopy was normal. The first colonoscopy detected diverticula of the left colon and fresh blood in the whole colon. The definitive bleeding site could not be identified. A technetium-colloid scan revealed an increased blood loss in the right colon. A second colonoscopy performed at the same time confirmed a right sided bleeding and an active capillary bleeding in the coecum without any mucosal lesion was identified.

As during the patient's first stay at hospital the site of lower gastrointestinal bleeding could not be determined, the patient was treated by transfusion and oral anticoagulation was stopped. The bleeding stopped spontaneously within a few days. At the third rebleeding episode examinations located the bleeding in the right colon, and a right hemicolectomy was performed. After the operation a piece of chicken bone was detected in the wall of the coecum, which had led to a chronic mucosal bleeding after penetration of the colonic wall. After surgery the patient recovered quickly and no rebleeding recurred.

Identification of the exact origin of lower gastrointestinal tract bleeding remains difficult. As the mortality rate as well as the re-bleeding rate in blind segmental colectomy is very high, compared to the resection in patients, where bleeding site could be identified, the site of bleeding must found in any case.