STOMACH CANCER
Smoking causes stomach cancer. The risk of stomach cancer decreases after quitting smoking. Smoking also affects the risk of increased colorectal polyps and bowel cancer.
GASTRIC ULCER
Smoking causes peptic ulcers in people infected with H. pylori, a common bacterium. The painful ulcers occur in the stomach or duodenum (the small intestine that connects to your stomach). Smoking increases the risk of complications such as bleeding and perforated ulcers, which can be fatal. Peptic ulcers can be treated, but success is limited for people who continue to smoke.
Smoking has a number of effects on the stomach and intestines that may promote the development of peptic ulcers. For example:
- Smoking promotes reflux of duodenal contents back into the stomach.
- Smoking increases the acid concentration in the duodenum and makes it susceptible to H. pylori infection.
- Smoking constricts the small blood vessels in the stomach, reducing blood flow. This can damage stomach tissue and slow the healing of ulcers.
- Smoking reduces the production of natural substances that help protect the stomach and duodenum from tissue damage.
Most of the effects are short-lived and will return within minutes or hours of stopping the drug. This suggests that people who quit smoking are less likely to develop ulcers than those who continue to smoke.
Crohn's disease
Smoking increases the risk of Crohn's disease, a chronic inflammatory bowel disease. People with the disease experience pain, severe diarrhea, and intestinal bleeding. Treatment includes surgery to remove part of the intestine. Smokers with Crohn's disease are more likely to have more severe symptoms, and to have surgery earlier and more often than nonsmokers.
