Dear Dr. Gott: Please tell me what causes polyps in the colon. I had 11 removed in 2001, and now I have to have a colon test every year. Every year I have at least two or three more new polyps removed. Am I at risk of colon cancer? I constantly worry that I am.

Reply: Polyps are small growths that usually arise in the lining of the colon or sinuses. They are generally noncancerous, but, rarely, some types of polyps may be premalignant.

There is no clear cause for polyps except those associated with familial polyposis. This condition is caused by a mutated gene and therefore runs in families. These polyps have a high malignant potential and generally occur around puberty.

You don't give your age in your letter and do not mention whether any of the polyps were found to be cancerous. However, I believe that you would have been told if they were cancerous or precancerous and would be receiving appropriate treatment. I assume that they are benign, harmless growths that you shouldn't worry about.

Polyps are best treated by removal during colonoscopy. You appear to be receiving appropriate care and, by having the procedure annually, as any new polyps are removed, your cancer risk is lessened. I don't believe you are at a particularly high risk of cancer, since you have been having regular removal of your polyps for over six years.

If you have any change in bowel habits, such as diarrhea or constipation, black stool, rectal bleeding or pain, you should see your physician as soon as possible. These may be signs of intestinal abnormalities that should be tested immediately.

Make an appointment to discuss your concerns with your gastroenterologist (or the specialist who performs the colonoscopy). He or she is familiar with your case and is best suited to answer any questions you have. To make sure you have all your concerns answered, write a list of questions and bring it to the appointment. I am sure that your physician would be more than willing to provide written answers for you to take home.

To give you related information, I am sending you a copy of my Health Report "Irritable Bowel Syndrome." Other readers who would like a copy should send a long, self-addressed, stamped envelope and $2 to Newsletter, PO Box 167, Wickliffe, Ohio 44092, USA. Be sure to mention the title.

Dear Dr. Gott:While using an oestrogen cream, I was struck by the thought that if this just passes through my skin and into my system, what do my sunless tanner and teeth whitener do to me? There isn't a day that goes by that I don't use at least one product on my skin or in my mouth. Do all these chemicals have risks for me? What's your opinion?

Reply: To my knowledge, sunless tanner and teeth whitener are safe. There have been no "red flags" to suggest any serious toxic reactions from the compounds. Some people might have allergic reactions to these products, but they are generally mild, and symptoms stop when the product is discontinued or shortly thereafter. If you are truly concerned, speak to your physician or pharmacist, who might be able to help.

Doctor Gott is a retired physician and the author of the book "Dr. Gott's No Flour, No Sugar Diet," available at most chain and independent bookstores, and the recently published "Dr. Gott's No Flour, No Sugar Cookbook."