Behcet's Disease - Now have constipation, diarrhea and back pain

Hi,

I was diagnosed with Behcet's Disease in December and am taking colchicine. Everything has been good until recently. Today my body has been bothering me... I woke up feeling very nauseous and hungry, and then when I eat, I get sick to my stomach. I had a fine afternoon, so when I had dinner, I didn't think anything would happen. Instead, I became very nauseous and felt those stomach aches I had been getting - feels like all the organs are cramping or crashing into each other. Anyways, I tried to go to the bathroom, nothing. I started feeling better, and then about 15 minutes later, it started again, but worse. I went to the bathroom and ended up having a bowel movement that seemed a bit constipation like to me. I felt relieved after and figured it was just from that, but maybe 10 seconds went by, another constipation-like bowel movement and then diarrhea. It all happened one after the other. The diarrhea was more liquidy green. After the final round of that passed, I felt fine, but noticed a pain on the left side of my back (left-center)... Is there anything I should do? I am a bit nervous because of my condition and appreciate all the advice I can get.

Thanks