A pulsating arterial bleeding from a diverticulum, situated in the colon sigmoideum, was identified and stopped during video-documentation in a 70 year-old man. After injection with a solution of suprarenin, the diverticulum was turned out like a balloon into the colon and didn't show any signs of further bleeding until the patient was prepared for a semi-elective resection of the sigmoid. This case demonstrates that emergency endoscopy is an effective method for diagnosis and even therapy of massive lower intestinal bleeding which eventually has to be supplemented by radiological techniques like scintigraphy and arteriography.