Controlled my IBS with diet, excercise and fiber

A few years back I was diagnosed with IBS-C (constipated) and through diet and excercise changes as well as adding fiber to my daily diet I seemed to have it under control.  However due to some changes in my life I put back on a lot of the weight I had taken off (about 25-30 lbs) and until recently still was not having any IBS issues but now that I have decided to get back in shape I am running into a problem I was wondering if anyone could help me out in finding a solution to.  With strenous (anerobic) excercise for a day or two afterword I will have really bad heartburn.  First time I blew it off as having had spicy mexican food about 3 hours before the hard workout (mt. biking with some steep hills that put me into a very anerobic/oxygen debt state).  But now it has happened about three times in a row and it seems to last a day or two after the hard workout.  It is definitely heartburn and not a cardiac issue (had a full workup not all that long ago and also the heartburn gets worse with food and includes gas and burping).  Anyone else run have experience with this?  Any clues short of cutting back on excercise to help resolve the issue.  TUMs do help for short term but the heartburn comes back within an hour or if I eat or drink anything.

Thanks.

Exercise can cause heartburn,especially upper body exercise. I really don't know the answer. Perhaps changing the time you exercise in relation to eating or possibly taking something like Gas-x before you eat. From what you are saying about the gas my guess would be that you are swallowing air while exercising which causes gas and burping. Perhaps you need to work on your breathing more. Just a thought for the gas part.