Updated 20 December 2017

Complications of peptic ulcers

Complications of peptic ulcers include bleeding, perforation and obstruction of the gastric system.


People who have peptic ulcers generally continue to function quite comfortably and some ulcers heal spontaneously without medication. Therefore, the main problems due to ulcers are their complications, which include bleeding, perforation and obstruction of the gastric system.


If you have a bleeding ulcer, you have black (resembling tar) stools (called melaena) and feel weak. You may feel as if you are going to faint when standing and you may vomit blood.

The blood in the stomach is usually changed by gastric acid so that has a grainy, black appearance (looking like coffee grains) – referred to as haematemesis. The initial treatment consists of rapidly replacing lost body fluids. If bleeding is severe or persists, you may need a blood transfusion.


In the case of a perforated ulcer (when an ulcer makes a hole right through the stomach wall), the gastric contents leak into the abdominal cavity. This causes acute peritonitis (inflammation of the abdominal cavity). You have sudden and severe abdominal pain, which worsens whenever you move. The abdominal muscles become rigid and board-like. Surgery is usually urgently required.

Gastric obstruction

The obstruction usually occurs at or near the pyloric canal. The pyloric canal is the naturally narrow part of the stomach where it joins the upper part of the small intestine, the duodenum. People with obstruction have increasing abdominal pain and they usually vomit undigested or partially digested food because it cannot pass into the rest of the digestive tract. They also report weight loss and a diminished appetite. The doctor usually does an upper endoscopy to exclude the possibility that gastric cancer may be causing the obstruction.

Read more:

Preventing peptic ulcers

The symptoms of peptic ulcers

Treating peptic ulcers

Revised and reviewed by Dr John P Wright MBChB, MRCP (UK), PhD. Gastroenterologist in private practice, Cape Town. February 2015

Previously reviewed by Prof Jan van Zyl, Department of Gastroenterology, University of the Free State, July 2011