More than 30 causes for long-lasting diarrhea

DEAR DR. DONOHUE: I need your help. I have had diarrhea for three months. I have tried Pepto-Bismol and Kaopectate. Neither worked. I have to use the bathroom 10 or more times a day, and I have become a prisoner of my home. How can I stop this? -- L.C.

ANSWER: Diarrhea lasting longer than four weeks is chronic diarrhea and has a list of possible causes numbering more than 30. Less-prolonged diarrhea is most often caused by infectious agents -- bacteria or viruses. Chronic diarrhea is caused by germs less often, but examples of infectious chronic diarrhea do exist. The one-celled organisms Giardia and Entamoeba are examples of such causes.

You are not going to get to first base without the help of a doctor. If you have already seen one without finding an answer, then it's time to see a gastroenterologist, a specialist in digestive-tract diseases.

I find it impossible to even venture a guess. Have you lost weight? Do you have stomach pain? Can you relate it to any one food? Were you taking antibiotics before it started? Have you been camping? Answers to these questions narrow the search.

Illnesses that prevent food absorption cause chronic diarrhea. Examples are celiac disease -- an intolerance to wheat, barley and rye -- and an intolerance of milk sugar, or lactose intolerance. Pancreatic problems lead to diarrhea because the pancreas makes enzymes that digest food. Without those enzymes, food rushes through the digestive tract. Chronic diarrhea is seen in Crohn's disease and ulcerative colitis, both inflammations of the intestinal tract. An overactive thyroid gland often leads to diarrhea that doesn't stop.

While you're waiting to see the doctor, you might want to try medicines like Imodium A-D or Lomotil. They can often slow the passage of food through the tract. They are not cures, however.

DEAR DR. DONOHUE: I am in the fifth month of pregnancy, and I have a brown blotch on my forehead. At first it was light, and I could barely notice it. Now it's quite dark, and other people comment on it. My doctor says it will go away. I'd feel better if you tell me that too. Will it go away? What is it? -- N.R.

ANSWER: It's melasma, something that happens to many women during pregnancy. It has to do with the hormones produced during pregnancy. It can appear on the forehead, the cheeks, the nose, chin or the upper lip. For most women, it disappears within a year after delivery.

Birth control pills, a misbehaving thyroid gland and too much sun are other causes of melasma.

You must stay out of the sun, or the discoloration will darken. If you go outside, apply sunscreen.

If you happen to be one of the few women whose melasma doesn't leave, dermatologists can treat it with bleaching agents or a chemical peel. Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853- 6475. Readers may also order health newsletters from www.rbmamall. com. 2006 North America Syndicate Inc. All Rights Reserved