Q. I've read about the recommendations for mammography to detect breast cancer, but worry about the exposure to x-rays. Wouldn't getting all those mammograms actually cause a lot of cases of breast cancer? Is mammography really worth the risk?

A. The risk of mammography causing breast cancer is so slight that, if it exists at all, it's probably too small to measure.

The very low doses of radiation used in modern mammography (breast x-ray) equipment have never been shown to produce harmful effects. Basing their judgments on studies of exposure to high-dose radiation, scientists have made various estimates of the potential risk of routine mammography.

Some experts argue that it's unlikely for mammography to cause any breast cancer at all. Others have estimated a theoretical risk of one case of breast cancer per year for every 2 million women undergoing routine mammography screening.

Under the worst of circumstances, this would result in one death from mammography each year for every 4 million women screened. To put things into perspective, this risk is the equivalent of smoking one fourth of a cigarette, driving 15 miles by car or simply being a man 60 years of age for five minutes.

On the other hand, there are more than 120,000 new cases of breast cancer each year and 37,000 deaths from this disease. Using worst-case estimates, mammography would add 160 years of life expectancy to women as a group for every year taken away.

Because the risk of mammography is probably closer to zero, I support the recommendations of the American Cancer Society: Initial mammogram at about age 35, mammograms every 1 to 2 years between 40 and 50, and yearly mammography after age 50.

Q. I gave birth to my first child last July. He was quite large for me, and I have a large scar from the episiotomy -- the incision of the perinium. Ever since, I have occasionally had difficulty controlling my bowels. I faithfully do the Kegel exercises to strengthen my pelvic muscles, but still have problems.

Will this condition improve? What can I do to speed up the healing? Will I be in even worse shape should I have another child, or could I be "sewn up" better?

A. Some women experience difficulty with bowel control after childbirth, particularly after having many babies. In some cases, the problem doesn't show up right away, but begins to develop in later life as the muscles of the pelvis lose some of their firmness.

This complication is more likely if you've had a tear of the anal sphincter -- the muscle responsible for bowel control -- either from a widening of the episiotomy incision or the childbirth itself. Occasionally, not all of the muscle fibers heal back together, leading to loss of bowel control.

If the sphincter isn't intact, the Kegel exercises to firm the pelvic muscles probably won't restore bowel control. I also wouldn't expect much more healing to occur this long after your delivery. In other words, I don't think your condition will improve much more on its own.

It is possible that another delivery would worsen your condition, but there is some treatment that should help. Rectal surgery to sew the sphincter back together again is usually effective in solving or significantly helping this problem. I'd recommend asking your doctor for a referral to a rectal surgeon for an examination.

Jay Siwek, a family physician from Georgetown University, practices at the Fort Lincoln Family Medicine Center and Providence Hospital in Northeast Washington.

Consultation is a health education column and is not a substitute for medical advice from your physician. Send questions to Consultation, Health Section, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Questions cannot be answered individually.