I'm sorry to hear about your sister. I work at M.D. Anderson C.C. and I know for a fact that we treat a lot of intestinal types of cancer. Chemo, Surgery and Radiation therapies are not the only treatment Anderson offers. The more promising treatments that are being offered tend to be a combination of targeted therapy, Gene Tx, Chemo, Rad, Surg. Targeted & Gene therapy shows a lot of promise since it seeks and hits the malignancy more accurate than a regular chemotherapy.
It will really depend on the patient's tumor score, general health, other illnesses, etc. Generally the lower the stage the better the prognosis and availability of treatment options.
Sloan Kettering, Mayo are also top of the line centers. In fact you'll see our faculty mixed with docs coming from the said institutions. As for US News reports Best Cancer Hospital, we've shared with Kettering the top 2 places for atleast 5 yrs now. This year was 2nd place, but if my memory serves me right we had 3 1st places in those 5 yrs.