Re: uncontolled bowel movements
Take your son to a GI doctor and ask him to do a colonoscopy. While doing the colonoscopy have him take samples for biopsies. I had the same thing in my 50's and it turned out to be a condition called Clostridium difficile. It's where the bad bacteria take over the good bacteria and cause this diarrhea and uncontrollable bowel movements. I was treated and am now fine. There are two medications they use for this. One is Flagyl and the other is Vancomycin, which is very expensive. A 14 day course costs approximately $1,200. Hopefully you have good insurance. I do and it only cost me $40 co-pay.
Please take you son to a doctor right away. If you need any more information on this, just let me know and I'll try to give you more info.