Gastroduodenal perforation is usually accompanied by bleeding. In mild cases, the bleeding may appear as positive occult blood in the stool, tarry black stools and vomiting of coffee-coloured material; when the bleeding is heavy, there may be blood in the stool, which may be dark red or even fresh; when the bleeding is near the pylorus, there is often vomiting of blood when the bleeding is heavy. The bleeding is usually accompanied by severe abdominal pain.