What I would suggest is this:
First, look for the MD Anderson booklets on bowel control -- there are several of them. They have good advice for what to eat and what not to eat in various stages of colo-rectal cancer treatment. Try Google with keywords like, BOWEL MANAGEMENT MD ANDERSON, and then look for the MD Anderson booklets listed in the list of outputs.
Second, read the following article,which explains the different types of diets depending on the stage of treatment of the patient and the type of colo-rectal cancer involved. The recommended diets are different depending on whether it is colon cancer or rectal cancer, and whether or not any any surgery or radiation was done on or near the rectum or sphincter. There is no "one-size-fits-all" diet for colorectal cancer. You must customize your diet according to the type of treatment you have had as well as the location of your primary tumor.http://www.cancerresearchuk.org/about-cancer/type/bowel-cancer/living/diet-after-bowel-cancer
Third, try to take advantage of the nutrition specialists available at MD Anderson. At least they should be able understand nutrition within the context of cancer. But when you schedule a meeting with a nutritionist, try to get one that is very familiar with colo-rectal cancer, as opposed to other types of cancer such as breast cancer or lung cancer. This is because eating of course involves the gastrointestinal tract, and whatever you eat can have good or bad effects on the recovery of your colo-rectal cancer surgery. You need a nutritionist who really understands that some things you eat while in surgery-recovery mode can have adverse effects on the overall healing process. They have to understand that all of the food that you eat will have to pass through the area that is under active treatment, and that certain kinds of foodstuffs, although very nutritious, may not be the best thing for a sensitive colon to process in the post-surgery context. They also have to understand that the main things to watch out for are chunky, high-fibre foods (e.g.,muesli, trail mix, Waldorf salads, popcorn), gas-producing foods, such as beans and carbonated beverages, as well as constipating foods. For a diet to be good it must not only be nutritious and varied, but it must also be balanced and must not disrupt the natural flow of food through the gastro-intestinal tract.
You're lucky that you have a contact with MD Anderson. They should be able to sort things out for you eventually.