Which of the following complications can occur if an ulcer is left untreated?

If an ulcer is left untreated, the following complications can occur:

Bleeding: Untreated ulcers can erode blood vessels, leading to gastrointestinal bleeding, which may cause symptoms like black or bloody stools and vomiting blood.

Perforation: An untreated ulcer can create a hole in the wall of the stomach or intestine, leading to peritonitis, a serious abdominal infection.

Obstruction: Chronic ulcers can cause swelling or scarring, leading to a blockage in the digestive tract, which can impair the passage of food and cause pain and vomiting