Weird P&B Shakes Problem - Part 2

It turns out that the "discomfort" I felt was some kind of acid reflux. It took a whopping 15-20 TUMS to finally get it to stop hurting. I had an unusually large bowel movement today and vomitted up a dark black pulp of some kind. I am feeling a general sense of malaise, like I have a flu, but without any respiratory symptoms. I've had Crohn's Ulcerative Collitis and severe constipation for 7 years and am hoping that cleaning out my system with P&B shakes followed by probiotics will help. Can anyone offer any further suggestions about what I should do? I am feeling absolutely awful!