I have done a lot of online research on IBS, as I was dx with it last year after much abd pain. From what I can tell, it is usually associated with bloating and diarrhea, but can also be associated with constipation.
I never really had too much trouble with anything like that other than the bloating and occasional constipation, which I pretty much contribute to my poor diet.
I started having severe abd pains about a week after I had my gallbladder removed. I never had any problems before that. I had it removed because I have hepatitis and had a CT of my abdomen that showed gallstones, and my surgeon opted to remove my gallbladder due to the risk of a stone getting "stuck" and causing liver damage. I otherwise had no symptoms or reasons to get it removed.
Like I said, my abd pain started about a week after that, and would start in the epigastric area as pressure, and go down to my navel area and wrap around to my lower back. It was so bad that I visited the ER three times, only to have everything come back negative and get RX for prevacid, etc. The meds didn't help. The only thing that helped was pain meds.
I would also bloat severely during these episodes that would last from 30 min to 2 hours up to 3 times a week (not related to diet as it happened on full and empty stomach)....the episodes have gradually decreased over the last year, in frequency, length and severity. The only med that DID help was carafate taken PRN, which doesn't make any sense since that isn't how the med works.
In any case... maybe it IS IBS that I have... but thankfully it has gotten less severe.
I know that probably doesn't answer your question, but I would tell your friend to go to a gastroenterologist because I know how bad abd pain can be.