If you had the surgery for colonic inertia, I would imagine that the remaining colon is giving you problems. I think you really need to pursue this with your surgeon.
I did not have colonic inertia, I had UC. But I think the standard treatment is to remove the entire colon and connect the small intestine up to the rectum. Yours is the second comment I have seen about a CI patient who had a portion of the colon left, the other person is having problems too. I would ask your surgeon why he/she opted to leave a portion of the colon in place and did not remove the entire organ?