Our surgical colleague has answered this question below in his comments, and I agree with everything that was written. I'll reprint it here since comments don't get saved:
"The significant majority of people who have their GB removed have no ill effects at all: the GB stores bile, does not make it. So the same amount of bile still gets into the intestine which is where it does its job. Bile storage was important before civilization, when you might go for days between meals. Since we eat regularly, we don't need to store bile. It's true that in some people, there are side effects: mainly diarrhea, especially after a very
fattyXanthoma meal. Most don't have it; those that do can usually control it easily. Nothing is 100% in medicine, however. The only option to surgery is no surgery; a stone that size will not dissolve. It's possible he could control attacks with diet; but many people have attacks no matter what they eat. The odds of a 15 year old who's already had an attack making it through with no more are pretty slim."
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b
My 48 year old husband had his Gallbladder removed in April 2004
and is having complications,hence what I'm doing on this site.As near as I can find out he is suffering from what is called DUMPING SYNDROME which is a complication that can be a result of surgery.I knew to look for this after I visited with a nurse.When searching under that title I found DrDonnica.com and there was the connection to his surgery. Now I know that not eveyone will have complications due to the surgery but my husband is,his Gallbladder was only operating at a minimal of it's capacity so he chose removal. On the other hand I've had trainning in natural health and know from others in the field that any condition can be treated and maybe even reversed. If I were you I would seek out all the help/options prior to surgery that I could find. I have a friend who was suffering much the same as your son but opted to change his diet and did a cleanse and is doing fine. Surgery is not always the answer and as my husband is finding out can bring on more complications than what you had prior to it.Good luck what ever you decide.
Thanks