I found brown rice -- "riz complet" in French, and distilled water, and followed the diet exactly. Results have been very good, and fast. The terrible gas was gone on day 2, and the frequency of stools diminished until it was only once per day from day 7.
I am starting to introduce other foods now and I will observe the effect on consistency of the stool.
I would appreciate if you could tell me some of the foods that I should avoid introducing during these early stages, the ones that I should leave for later when the colon is fully recovered. In particular: fruit and ground flax, as these are part of my regular diet, but also white rice, beans, tomatoes, pasta and bread.