hi, i have a similar problem to you! had ibs for years then had my large bowel removed due to Constipation last year. I was told to stay off high fibre as it was also making me worse. I just wonder all those years of pain etc... if it was caused because of too high a fibre intake obv recommended by the docs. I was still getting C after the op, and a few months ago a dietician put me on to a low res diet then i could gradually start increasing my foods again. But the same thing happens.
For me sticking to a low fibre diet is difficult as i have had to pump myself full of the stuff since wee, but i am sooooo much better now. I have my off days but who cares at least it is not every day.
I would stay away from, cauli and brocoli stalks, florets in small amounts. no potato skins or bran,and try to stay away from fruit. Except grapes and melon, other fruits should be canned, but no pineapple, too fibrous. No wheat just plain white breads etc.... they also say you should stay away from oats and corn but i actually find these help. You still can have fresh fruit juice with no pulp. Dinners can be difficult. Chicken, white rice, bolied or mash potatos, salads, no tom seeds, green beans, aspargus, ok, no tough meat or fatty meat either. Hope ome of this helps but a food diary, with pain etc.... will let you see what affects you most then you can stay away.