Preventing "horsewoman's tan"

Q: I've been advised to use diaper-rash ointment containing zinc oxide to keep my horse's muzzle from getting sunburned while he's grazing. I've been wondering if this would also work to keep me from developing a "horsewoman's tan." All of the sunscreens I have tried help me avoid sunburn, but I have brown arms from the edge of my gloves to the edge of my short-sleeved shirts.

A: For decades, lifeguards have used white zinc oxide to keep their noses from burning. It blocks both UVA and UVB rays and provides excellent protection.

You could try the diaper-rash ointment or get a sunscreen that contains both zinc and titanium. New formulations contain microfine particles that don't leave a distinctive white color. Human sunscreens can also be used on horses to keep pale skin from burning.

Q: In the recent past, I took Alli for weight loss. To my amazement, my constant constipation disappeared. I now keep it on hand for constipation.

A: Alli is over-the-counter orlistat. It has been prescribed under the name Xenical. Diarrhea and increased bowel movements are common side effects of orlistat, so it's not surprising that it might combat constipation.

Q: I have diarrhea regularly. Your column has some great suggestions for more natural remedies.

What I have the most success with is Pepto-Bismol. Are there any ingredients in it that would make it harmful to take one or two tablets three or four times a week?

A: Pepto-Bismol has a long history dating back to the early 20th century. It was originally developed to treat severe diarrhea in babies.

The active ingredient is bismuth subsalicylate. It remedies a wide range of digestive problems, including heartburn, diarrhea and nausea. Since the label says you can safely take up to 16 tablets in 24 hours, your dose is not unreasonable.

Despite its good safety record, Pepto-Bismol is not meant to treat a chronic condition. Too much bismuth can lead to loss of appetite, canker sores and poor absorption of nutrients. The salicylate component can cause ringing in the ears. You should check with your doctor about the cause of the diarrhea to see if that can be addressed.

In their column, Joe and Teresa Graedon answer letters from readers. Write to them c/o King Features Syndicate, 888 Seventh Ave., New York, NY 10019, or via their Web site: www.peoplespharmacy.org