An ulcer is an open sore in the stomach or intestines. If left untreated, it can cause internal bleeding, which may be fatal in rare cases. In addition, an ulcer can eat a hole in the wall of the intestine or stomach, increasing the risk of infection of the abdominal cavity. They may form scar tissue that obstructs the passage of food through the digestive tract.
According to the National Institutes of Health, a person should seek immediate medical care if experiencing sharp persistent stomach pain, bloody or black stools or vomit that is bloody or resembles coffee grounds. This could indicate a broken blood vessel, a perforated intestine or stomach wall or an obstruction caused by scar tissue.Learn more about Wounds & Bruises