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.