Try eating 1/3 to 1/2 cup of a cereal called "100% Bran", its pretty high in protein and it has 8gm fiber per 1/3 bowl. I eat about a cup of this a day, but it doesn't help that much for IBS symptoms- just keeps things regular. I had this exact same problem for awhile, talked to my doc, but he was not familiar with IBS treatments so I researched it myself. Now I take 2-3 tablespoons of mineral oil and 1 capsule of pericolace before bedtime. All the problems just went away, no cramps, no mucous, and ,even though I eat like 300gm of protein a day, I stopped having those nasty protein farts.