Ulcers were believed to be caused by stress, smoking, anxiety, and/or a diet rich in spicy foods. However, research has shown that most ulcers are caused by a spiral-shaped bacterium known as Helicobacter pylori (H. pylori). The other common cause of ulcers is nonsteroidal anti-inflammatory drugs (NSAIDs).

When we eat, food passes down the esophagus (throat) and into the stomach. There, hydrochloric acid and pepsin (an enzyme) continue the digestive process that started with the saliva in your mouth. Next, food passes to the duodenum (small intestine) where the digestive process continues. An ulcer is an area of stomach or duodenum that has been damaged by the digestive enzymes and stomach acid.

How H. pylori causes ulcers is not yet fully understood. We do know that:

  • The bacteria can live in the stomach because they attach to cells and produce an enzyme that stops the corrosive effects of stomach acid.
  • The bacteria damages the protective mucous layers of both the stomach and the duodenum.
  • Not everyone who has the bacteria will develop an ulcer.
  • Being infected with the bacteria is also a risk factor for developing stomach cancer.

An ulcer that goes untreated can cause several problems in the abdomen, such as:

  • Internal bleeding
  • Perforation (a hole) in the stomach or duodenum allowing food and bacteria to spill into the abdomen and cause infection and irritation
  • Blockage of the opening between the stomach and duodenum due to chronic inflammation that leads to swelling and scarring