gerd and ibs

Hey guys, I am a 24 year old male and i've had heartburn for most of my life. I've always self-medicated with Tagamet HB. On and off for the last few years I've had symptoms of IBS, namely frequent diarrhea and constipation. It was like periods of a week or two with diarrhea every day, happening a few times a year. In the last 2 years I've started getting worse and more frequent heartburn so i've been taking 2 Tagamets at a time, sometimes up to 8-10 a day. I'd say I average about 4-6 per day. I am in the middle of probably my worst episode of IBS symptoms in memory, with pretty frequent and severe abdominal pain and frequent diarrhea. I have also had some episodes of constipation. I never thought about it before but reading someone else's post got me thinking. Could my IBS be caused by taking too much Tagamet? Intuitively it seems like constantly reducing my stomach acid might mess with my digestion. Could Tagamet be causing IBS? My heartburn is bad enough that I can't to stop medicating just to test this hypothesis. I know the solution to both problems is to lose weight and I am going to, but what should I do in the mean time? And don't just say 'talk to your doctor'. :')