digestive disorders
Short Bowel Syndrome
Introduction
Short bowel syndrome is a disorder causing diarrhea and poor absorption of nutrients ( Overview of Malabsorption ), which often occurs after surgical removal of a large portion of the small intestine. This disorder often occurs after a large part of the small intestine (usually more than two thirds of its length) is removed. Diarrhea is the main symptom. After surgery to remove the bowel, people are given food and fluids by vein (intravenously). Some people must continue the intravenous feedings for life. Medications such asloperamideandcholestyraminecan help reduce diarrhea. 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 ( 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. The excess bile acids enter the colon and can cause diarrhea. Malabsorption causes diarrhea, typically beginning immediately after the surgery. Later, people develop undernutrition and vitamin deficiencies, such as Vitamin B12 Deficiency . 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. 