What would happen if the small intestine were removed from the body?
Answers
Common reasons for removing a large portion of small intestine are Crohn disease, a blockage of an artery that supplies blood to a large part of the intestine (mesenteric infarction), inflammation of the intestine caused by radiation (radiation enteritis), cancer, a twisted loop of intestine (volvulus), and birth defects.
Most digestion and absorption of food takes place in the small intestine. The consequences of removing a portion of the small intestine depend on how much is removed and its location. The small intestine is about 12 to 21 feet (about 4 meters) in length. If the middle part (jejunum) is removed, sometimes the last part (ileum) can adapt and absorb more nutrients. If more than about 3 feet (about 1 meter) of ileum is removed, the remaining small intestine usually cannot adapt. Before adaptation occurs, or if it does not, the intestines have difficulty absorbing many nutrients, including fats, proteins, and vitamins. If the end of the ileum has been removed, the intestines also cannot absorb bile acids secreted by the liver, which aid digestion and cannot absorb vitamin B12.
Malabsorption causes diarrhea, typically beginning immediately after the surgery. Later, people develop undernutrition and vitamin deficiencies.
The diagnosis of short bowel syndrome is based on the results of a doctor's evaluation of the person’s prior surgery, symptoms, and results of an examination.