Smoking can harm your digestive system in a number of ways. Smokers tend to get heartburn and peptic ulcers more often than nonsmokers, and smoking makes those conditions harder to treat. Smoking increases the risk for Crohn’s disease and gallstones, and it damages your liver. Smoking is also associated with cancer of the digestive organs, including the stomach, pancreas, and colon.
The stomach makes acidic juices that help you digest food. If these juices flow backward into your esophagus, or food pipe, they can cause heartburn or a condition called gastroesophageal reflux disease (GERD). The esophagus is protected from these acids by the sphincter, a muscular valve that keeps fluids in your stomach. But smoking weakens the sphincter and allows stomach acid to flow backward into the esophagus.
Smokers are more likely to develop peptic ulcers, painful sores in the lining of the stomach or the beginning of the small intestine. Ulcers are more likely to heal if you stop smoking. Smoking also raises the risk for infection from Helicobacter pylori, bacteria commonly found in ulcers.
The liver normally filters alcohol and other toxins out of your blood. But smoking limits your liver’s ability to remove these toxins from your body. If the liver isn’t working as it should, it may not be able to process medications well. Studies have shown that when smoking is combined with drinking too much alcohol, it makes liver disease worse.
Crohn’s disease is a chronic inflammatory bowel disease. This disease is an autoimmune disorder of the digestive tract. For reasons that are not clear, it's more common among smokers than nonsmokers. Although various therapies help to keep Crohn’s flares under control, it has no cure.
Smoking is one of the major risk factors for colon cancer, the second leading cause of cancer deaths. Routine screenings, such as a colonoscopy, can identify small, precancerous growths called polyps in the lining of the colon.
Some research suggests that smoking increases the risk of developing gallstones. Gallstones form when liquid stored in the gallbladder turns into material that resembles stones ranging in size from a grain of sand to a pebble.
Smoking is a risk factor for mouth, lip, and voice box cancer, as well as cancer of the esophagus, stomach, pancreas, liver, colon, and rectum.
If you smoke, try to quit. Seek medical help for smoking cessation if you need to. Giving up smoking will lower your risk for lung cancer and heart disease, and also reduce your risk for other digestive disorders.