Why is it that when a person vomits, it causes others to vomit — even when they don't have an illness causing it? Is this something triggered by the brain or is it something that happens by reflex (survival instinct) for someone to vomit since, perhaps, what the first person was eating may affect the second who vomits as well?

As the summer is soon to arrive, I was wondering what type of clothing should I wear to protect myself from the sun? Also, what color works best, light or black? I seem to be getting conflicting answers on the Internet. I am a fair skinned male. Thanks for your help!

As an avid contact wearer, I use saline solution to rinse my contacts daily before each use. Recently, a friend told me that many commercial saline solutions contain preservatives, which could affect the overall health of my eye. Is this something I should be concerned about? The saline I use has always felt comfortable so I never thought it could pose a problem.

Does a person's menstrual cycle regulate her bowels in any way? I have had some problems. The week before I get my period, I have loose bowels and the week afterwards I am quite constipated. Is this normal? Is there anything I can do?

I am a young, white, tan, female and I have noticed that my stomach has become discolored. It is almost spotted-looking. Is this the side effect from birth control pills, or does it sound like a more serious problem?

I have had Crohn's disease for 16 years and am in remission right now. Recently my boyfriend and I have been toying with the idea of anal sex, but I'm concerned about it given my health issues. I have a lot of thickening of the terminal ileum walls and worry that the "trauma" of anal sex could set off a flare up and be painful because of the narrowing. Any thoughts? I'm way too embarrassed to discuss this with my male doctor. Thanks!

A friend of a friend told me all about this ultraviolet/blacklight tattoo method. It was deemed unsafe earlier when it first came out, but apparently now it is completely safe. This friend of a friend said she does these tattoos all the time now and is really good about not scarring. So I'm not worried about anything like scarring being seen, I'm just worried about getting cancer and other accusations when ultraviolet tattoo first came out.

What natural food or herb can help soothe stomach ulcers?

I recently started taking birth control pills to help with my acne. But since it is considered a low dosage kind (Low Ogestrel, to be specific), I wonder if it is still an effective and safe contraceptive. Can I take this kind and not have to worry about getting pregnant?

I read that disposable contact lenses are actually worse for your eyes than the normal one-year ones because they allow less oxygen to go to your eyes, and the only advantage is that there are less cleansing problems. Also, it is claimed that inadequate oxygen to your eyes (possibly caused by prolonged wearing of contact lenses) leads to a condition when extra blood vessels sprout around the iris, which leads to sight problems at old age. Is that true?

I am very concerned because I normally wear (one-year) contact lenses from 8am to 8pm, and maybe to 12am during reading periods. I don't feel very comfortable with glasses because they give distorted visions and fatigue. I thought switching to disposable contact lenses would do my eyes good. My current lenses contain 38 percent water. Is this good enough?