From your mouth to your colon, your digestive tract is loaded with bacteria and so is a common site for a variety of infections or inflammations. Other digestive problems, such as constipation and irritable bowel syndrome, are usually caused by a faulty diet. Specific food intolerances can be corrected by avoiding certain foods; lactose (in milk) and gluten (in wheat, barley and rye) cause problems for many people.

All of these digestive problems can cause inflammation, and they may keep you from getting the nutrients you need or from making good food choices. Some digestive problems are difficult to treat, while others are easy; none should be ignored. The brief summaries below highlight some of the more common digestive problems; more information is available at my web site (see the link at at the bottom of this article. Check with your doctor.

BURNING AND BELCHING: Stress does not cause stomach ulcers; they are caused by common bacteria. Anyone with belching or burning in the stomach or esophagus should be tested and most should be given the one-week course of antibiotics that treats the bacteria called Helicobacter pylori and their relatives.

GAS: Whenever you change your diet, particularly if you add foods that contain fiber, you are likely to have an increase in intestinal gas. When carbohydrates (fiber and resistant starches are not broken down and absorbed in the intestines, they pass to the colon where bacteria ferment the carbohydrates to release gas. This is perfectly healthful and the problem will probably diminish as you build up a colony of friendly bacteria in your colon. Add new foods gradually; if the problem persists, check with your doctor.

CONSTIPATION: Gas is usually not painful unless you are also constipated, with pockets of gas stretching your colon where it is trapped by hard stool. The contents of your intestines are liquid until they reach your colon, where water is absorbed and stool is formed. If you don't drink enough fluid or eat enough fiber, the stool rapidly turns into hard stones. Try avoiding all foods made with flour, eating lots of fruit, vegetables and whole grains, and drinking plenty of water. If this does not correct the problem, check with your doctor. Constant use of laxatives can deprive you of essential nutrients.

GLUTEN INTOLERANCE: In some people gas, diarrhea, cramping and failure to absorb nutrients are caused by gluten, which is found in wheat, barley and rye. You can try avoiding these foods to see if your symptoms are relieved, or your doctor can do blood tests for celiac sprue. You should also be checked for nutritional deficiencies such as lack of B12 and iron.

LACTOSE INTOLERANCE: Half of the world's population develops gas and cramping after drinking milk because they lack the intestinal enzyme that is necessary to break down the double sugar in milk called lactose. If lactose is not absorbed in the upper intestinal tract, bacteria ferment it in the colon to release gas. If you are lactose intolerant, you can avoid dairy products or buy the lactose-free milk that is widely available.

IRRITABLE BOWEL SYNDROME, CROHN'S DISEASE, ULCERATIVE COLITIS: The term Irritable Bowel Syndrome may be used to describe alternating diarrhea and constipation that can be cured by following the dietary changes for constipation (above). However, if you have digestive problems that are chronic and disabling, you need a complete workup to find the cause; check with your doctor who will probably refer you to a gastroenterologist.