After surgeries, stool that makes yellow water and incomplete evacuations?

Hello! I've been having the worst times this year.

I had a colectomy in early June. They took 25 inches. I left the hospital on TPN. I finished the TPN but developed an abscess that required a JP drain. The drain caused a fistula to my intestines.

On August 19, I had a small resection to correct that fistula. Overall, I've recovered quite well, but there's been some issues.

My surgeon did a c diff. test on September 1 as a precaution but has not called to say I have it so I think I'm okay. I started remicade on September 2.

My issues are this:
-When standing too long, my stomach feels a bit achey.
-When I eat, I almost immediately feel like I had to have a BM. When I attempt, barely anything comes out
-my BMs are watery to mushy, and the water in the toilet is yellow and foamy - right after surgery, they had begun to form but abruptly stopped.
-I feel like a pressure in my lower abdomen quite often. It feels like I never fully complete my BM

My questions:
Am I being a hypochondriac? Are these normal reactions to recovering from these surgeries? Is the yellow, foamy, and incomplete feelings cause for concern? What could it be? My surgeon did not seem concerned but should I call my GI? Could starting remicade have anything to do with it?

I return to work tomorrow and I'm all nerves.