I have to deal with Crohn's, which is the close cousin of ulcerative colitis. Fortunately, I'm symptom-free at this point.
Anyhow, I don't have much trouble with whey. High quality stuff like synthepure doesn't give me trouble. Also I have had no problems with LBAs.
Some protein supplements actually have added iron - for ex Nutrex's - and this would be a bad idea for your friend, as iron increases inflammation in IBD.
On a tangent, some people w colitis have trouble with creatine.