Sometimes an ulcer may involve just the surface lining of the digestive tract. The person may then have a slow but constant loss of blood into the digestive tract. Over time, anemia may develop because of this slow blood loss.
If ulcers become larger and extend deeper into the digestive tract lining, they may damage large blood vessels, resulting in sudden, serious bleeding into the intestinal tract. This can be very dangerous. Without prompt medical treatment to stop the bleeding, a person could bleed to death. Blood transfusions often are needed when serious bleeding occurs.
If you are vomiting blood and/or material that looks like coffee grounds, or if you have stools that are black, look like tar, or are maroon or bloody, see a doctor immediately. The chances of successfully treating your ulcer are best if you see a doctor when you first notice any bleeding.
Perforation occurs when an ulcer eats through the wall of the stomach or intestine into the abdominal (belly) cavity.
Although perforation is a much less frequent complication than bleeding, it is still a significant problem in people who have unsuspected or untreated peptic ulcers.