The metabolic effects of intestinal resection in man

Abstract

This paper seeks to illustrate the importance of physiological principles in guiding effective and rational treatment. If the sites at which absorption normally occurs in the small intestine are known, it is easy to understand what pattern of malabsorption will follow a given resection. Patients with resections of the distal small intestine may be classified in three groups. A localized resection of the ileum may be associated with an isolated defect of vitamin B12 absorption (Group i) and such a patient therefore requires no other treatment than injections of this vitamin. More extensive resections of the distal small intestine cause steatorrhoea and creatorrhcea in addition to malabsorption of vitamin B12 (Group 2). Patients with such resections require a highprotein, low-fat diet in addition to treatment with vitamin B12. Providing sufficient proximal intestine remains to absorb glucose and folic acid normally, no other treatment is usually necessary. Massive distal resections, leaving only a few inches of the proximal jejunum, cause interference with the absorption of glucose and folic acid in addition to steatorrhoea and failure of B12 absorption (Group 3). Survival is possible after such resections, but prognosis should be guarded. The failure of resection of up to 8 ft. of the jejunum to interfere with the absorption of glucose, folic acid or fat indicates that the ileum is capable of taking over the functions of the proximal intestine. Even after a massive proximal resection the terminal ileum is capable of absorbing much of the dietary fat and B12 absorption remains normal. However, after such a resection steatorrhcea may be incapacitating unless controlled by a low-fat diet and high-protein feeding is best achieved when the protein is given in solid forms. It is important to recognize that remarkably little residual small intestine is necessary for life and survival is possible after even the most massive resection.