I don't know what I have really, but my old gastro told me I had an extra long colon. About 2 years ago my gut changed. Long story short I did try to Fodmap diet, but really didn't think too many foods are the culprit. I, too, have had chronic constipation, since I was a kid. I did try Linzess, and it was working, but then stopped. Magnesium 400 mg does nothing for me. I did a Fleet enema once, which really didn't work, and made me sick--legs shaking & felt like I was going to pass out. I was taking 3 Citrucel tablets a day, but that doesn't do much of anything. I think I took benefiter, metamucil in the past as well. Now I take Senokot-S every few days, which helps. My old gastro told me to buy Atrantil off the web. I took that for quite some time, and I believe it did help with my bloating. Might be something others could try for bloating & gas.