Al, I'm sure you're aware that I'm not a doctor, but here's what I've been told:
The gall bladder stores bile for use in the digestive process. It can become inflamed due to infection, or due to obstruction of its exit duct, which exits into the intestine. The obstruction may be due to a cyst or other growth, or due to a stone. Some stones show up on X-ray, others on ultra-sound, etc., depending upon their content. Gall bladders are removed laparoscopically (sp?) now whenever possible, but they will have your friend sign a waiver giving them permission to do a full open-abdominal removal if they see complications when they look through the scope. If a scope is all that's needed, it is usually an outpatient procedure, with just a couple of days at home to recover.
After removal, most patients have no dietary restrictions or medications. Some people find that there are certain foods which they cannot tolerate (maybe spicy, greasy, etc., or even some veggies), but most have no such issues.
Hope this helps -- they say it isn't a biggie any more.