I'm a 50-year-old female who lost most of my small intestine because of a blood clot that formed and stopped the flow of blood. I have seven inches of small bowel left. I lost one inch of the colon and the ileol-cecal valve. I do TPN (IV nutrition) four nights a week and two liters of hydration the other three. I eat five meals a day and drink oral rehydration salts. In just two years, I have had three IV line infections. I also know that TPN has very bad effects on the liver, kidneys and bones. What is the long-term outlook for someone in my situation?

B.H.

In a healthy person, the length of the small intestine is about 12-15 feet. Its function is to absorb nutrients, minerals and water in the diet. Important digestive enzymes are also reabsorbed and recycled in the small intestine.

People who've had a large part of their small intestine surgically removed often develop the condition you describe, which is referred to as "short bowel syndrome." The conditions that most commonly lead to surgical removal of significant portions of small intestine include Crohn's disease, radiation-induced damage of the intestine or loss of blood flow (intestinal infarction), such as you experienced.

In patients with short bowel syndrome, proper attention must be paid to the replacement of the lost nutrients. Thus, patients are usually given increased amounts of water, salt (to replace the lost sodium) and dietary supplements containing carbohydrates, proteins and special fats that can be absorbed without requiring digestion. Many patients with at least three feet of jejunum (the portion of the bowel that performs the majority of absorption) can be managed with oral nutritional replacement. However, for patients like you who have less remaining functional small bowel, oral replacement is unlikely to be adequate and nutrition is usually given via an IV line (parenterally).

Total parenteral nutrition (TPN) is given through a catheter placed in one of the large veins in the chest. TPN is often given in cycles, so that the majority is given at night (at a regular hourly rate) and the patient can go about daily activities without hassle.

There are several complications both of short bowel syndrome and of TPN used to treat it. In regards to short bowel, nutritional deficiencies can lead to bone disease (because of poor calcium absorption), gallstones and kidney stones. As you mentioned, TPN is often complicated by infections of the IV catheter, sometimes necessitating its removal and replacement. Other complications of TPN include liver disease, gallstones, diabetes and bone disease.

For people with short bowel syndrome, the prognosis depends on balancing the benefits of proper nutrition with the risks of the potentially serious complications associated with TPN. New therapies in development include small- intestine transplant, which is currently being used in selected cases. Some patients are also taking mucosal growth factors (such as glutamine or growth hormone), in hopes of stimulating the cells lining the remaining portion of small intestine to grow and increase their ability to absorb nutrients.