Smoking has been linked to many illnesses of the digestive tract. Some of these are relatively minor, such as increased belching, bloating and heartburn. Others are more serious, such as peptic ulcers, liver impairment and Crohn's disease. Finally, smoking can cause cancers in the digestive tract, including the mouth, throat and esophagus.

The effects of smoking on the digestive tract vary in severity. For example, the negative effect of smoking on the body’s ability to produce sodium bicarbonate – a substance that helps neutralize the stomach acid that contributes to ulcers – appears to last for only about 30 minutes after the patient stops smoking a single cigarette. Patients who smoke and later quit remain at increased risk for developing Crohn’s disease during their lifetime.

Smoking is one of the leading preventable causes of health disorders, including illnesses of the digestive tract. Tobacco contains many toxins that are harmful to the body. Smoking contributes to the development of heartburn and peptic ulcers, impairs the liver and may increase the risk of Crohn's disease.

Smoking can also cause cancers of the digestive tract, such as cancer of the mouth, throat or esophagus. Some research indicates that smoking may raise the risk of colorectal cancer. It can also contribute to health disturbances in the digestive tract that are less serious, but nonetheless bothersome. Air swallowed during smoking can increase the likelihood of belching, flatulence or bloating due to the extra air in the body. Smokeless tobacco can also cause these symptoms.

In addition to triggering illnesses of the digestive tract, smoking also causes a variety of potentially life-threatening disorders. These include lung cancer, emphysema (a chronic lung disease) and heart disease.

Smoking impacts several digestive disorders, including:

• Heartburn. A burning sensation in the upper abdomen or chest area that is caused by reflux of the stomach acid. Contrary to its name, it is a disorder associated with digestion, not the heart. Smoking weakens the esophageal valve at the end of the esophagus, keeping it from fully preventing stomach acid from refluxing up out of the stomach. Damage to the esophagus from smoking may make it less able to resist the damage from refluxed fluids.
  
  
• Liver disease. Liver disease is illness that affects the liver, one of the body’s largest and most vital organs. One of the most important functions of the liver is to process drugs, alcohol and other toxins so that they are removed from the body. Smoking appears to damage the liver’s ability to carry out these tasks, although this effect disappears once the patient stops smoking. Other research indicates that smoking may also worsen liver disease resulting from excessive consumption of alcohol.
  
  
• Peptic ulcer. A sore that forms in the stomach and upper portion of the small intestine, knows as the duodenum. Peptic ulcers occur when stomach acid and digestive juices break down and corrode the lining of the esophagus, stomach or the duodenum, the upper portion of the small intestine. Scientists know that smoking makes ulcers more likely to occur, less likely to heal and more likely to cause death. However, the reason for this remains unknown. It appears that smoking reduces the ability of the pancreas to produce sodium bicarbonate, a substance that helps neutralize the stomach acid that contributes to ulcers. This bicarbonate-reducing effect seems to disappear about 30 minutes after the patient stops smoking tobacco.
  

  

• Crohn's disease. An inflammatory bowel disease (IBD) that causes chronic inflammation and ulceration within the digestive tract. Ulcers (open sores in the intestinal lining) and inflamed tissue may swell, redden and bleed, often leading to bloody diarrhea, abdominal pain and cramping. Both current and former smokers are at higher risk for developing Crohn's disease, and smokers who already have the disorder are at increased risk for relapse and repeat surgery. The link between smoking and Crohn's disease is unknown, although it is believed that smoking might lower the intestine's defenses, decrease blood flow to the intestines and cause changes in the immune system that lead to inflammation.
  
  
• Ulcerative colitis. A type of IBD that causes chronic inflammation of the colon. It is a disease of non-smokers, and smoking seems to cause a reduction of symptoms in patients.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to smoking and the digestive system:

1. How does smoking impact my digestive health?
   
   
2. How long will it take for my digestive tract to recover from the effects of smoking?
   
   
3. Has smoking caused any irreparable damage to my digestive tract?
   
   
4. Can I eliminate the risk of developing certain digestive disorders if I quit smoking?
   
   
5. What are my chances of developing smoking-related heartburn?
   
   
6. How likely am I to develop liver disease due to smoking?
   
   
7. I’ve heard that smoking can increase the risk of having toxic levels of drugs in my system. Will this effect diminish if I quit smoking?
   
   
8. In addition to smoking, what factors may have contributed to my condition?
   
   
9. I want to quit smoking but it is very hard. Are there methods you can recommend to help me quit?
   
   
10. Would simply decreasing how much I smoke improve my digestive health, or must I quit altogether?