I guess I would ask your surgeon why he/she left part of your colon? I thought the standard treatment for colonic inertia is to remove the entire colon and hook the small intestine up to the rectum.
As for your back pain, this could be caused by the awkward position the body is positioned during surgery. I had the same pain although it was addressed in the hospital with an IV or Toridal, the most heavy of anti-inflammatories. In fact the drug is so potent that a patient can not be on it for more than 48 hours.
You might need to see a doctor about getting an Rx for the back pain, most likely go back to your surgeon.
dx proctitis in 1987
dx UC in 1991, was stable until 1998
1998 started prednisone, asacol, pentasa, nortriptylene, ativan, 6MP, rowasa enemas and suppositories, hydrocortisone enemas, tried the SCD diet, being a vegetarian, omega 3s, flax, pranic healing, yoga, acupuncture, probiotics
2000 lost all my B-12 stores and became anemic
2001 opted for j-pouch surgery- now living life med-free