The large bowel (colon) is divided into several segments called the ascending colon, transverse colon, descending colon a sigmoid colon and rectum. In a healthy person, other than fluid and calcium absorption, the colon has a limited absorptive capacity and its main function is to absorb water and minerals, and to store waste matter (stools or faeces). Colon resection thus impairs the ability to maintain fluid and electrolyte balance. The operation is designed to remove approximately half of large intestine and this is so because of the blood supply to the bowel rather than extensive disease.
Following a colectomy, a diet high in calories, but low in fat is generally advised. It should also be rich in protein, vitamins, and minerals. Fluid intake should be adequate and include water, juices, and milk, each day to replace the extra fluid that will be lost in the stool. About 20% of patients notice that their bowel movements are more frequent and looser.
It may be wise to avoid high-fiber foods and foods with hulls, peels, and seeds during the first weeks after surgery. When the doctor allows resumption of normal diet he may begin with small amounts so that he can see how his intestine adjusts to digesting them. He should avoid any medications that is long-acting or sustained release.