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?

I've been eating the yogurt Activia and have felt less stomach grumblings since. I switched to just a low-fat yogurt for cost reasons and have had the grumblings come back. Is Activia really better for digestion or is this all in my head?

The few times I have tried anal sex, I get a horrible case of the farts afterwards lasting hours. I do not have the ability to hold it and it's very embarrassing. Is there anything I can do ahead of time or after to stop this?? Thanks

For years now I've been digesting my meals within an hour or less. I am able to see whole food in my bowel movements of meals that I have just eaten. Any idea as to what's wrong?