Ever since I was a child, I've had A LOT of stomach problems. A few years ago, I was diagnosed with acid reflux, and I continue to suffer with frequent heartburn. I also get horrible stomach aches and my entire stomach bloats up and I get sharp pain under my rib cage all the way down to my lower abdomen. I also frequently have problems with constipation and sometimes go 3-4 days without having a BM. For about a month now, I go through periods where I am constipated and have horrible stomach pain and then have severe diarrhea for days (not laxative induced). I'm either constipated, or I can't stop having BMs, with crippling stomach cramps either way.
I have considered the possibilty of having IBS, but is there a chance it could be something more serious like Chron's disease?

Anyone else have experiences like this?
Any suggestions?