Dr Deepak K Agarwal
The writer is senior consultant gastroenterologist, hepatologist & endoscopist and is running a successful medical Centre in Lucknow
Short bowel syndrome is a complex disease that occurs due to the physical loss or the loss of function of a portion of the small and/or large intestine. Consequently, individuals with short bowel syndrome often have a reduced ability to absorb nutrients such as fats, carbohydrates (sugars) vitamins, minerals, trace elements, and fluids (malabsorption). The specific symptoms and severity of short bowel syndrome vary from one person to another.
The symptoms and severity of short bowel syndrome can vary greatly depending upon the length and function of the remaining or undamaged portion of the small intestine. Because short bowel syndrome can vary so greatly, it is important to note that affected individuals may not have all of the symptoms discussed below. Affected individuals or parents of affected children or infants should talk to their physician and medical team about their specific case, associated symptoms, and overall prognosis. Although symptoms of short bowel syndrome vary, diarrhoea is common. Diarrhoea can be severe and can cause dehydration, unintended weight loss, a general feeling of poor health (malaise), lethargy and eventually malnutrition. Additional symptoms include cramping, fatigue, weakness, bloating, and heartburn. Individuals may have pale, greasy stools that contain excess amounts of fat (steatorrhea). Short bowel syndrome may cause malnutrition. Malnourishment can result in swelling (distention) of the abdomen, dehydration, loss of muscle mass, dry, flaky skin, swelling of the tissues of the legs and feet (peripheral edema), and weakening or wasting away of the muscle of the temples (temporal wasting) giving the temples a hollow appearance. Short bowel syndrome can lead to poor growth in infants and children due to undernutrition and lack of the proper building blocks for normal growth and development.
Surgical removal (resection) of a portion of the small intestine is the most common cause of short bowel syndrome. However, short bowel syndrome can result from any disease, injury, or condition that hinders or prevents the proper function of the small intestine, even if the overall length of the bowel is unaffected. However, the removal or loss of a segment of the small intestine does not necessarily result in short bowel syndrome. Often, additional factors play a role in the eventual development of the disorder. Such factors include the following: The specific segment of the intestines that is lost, the remaining length of the small intestines, whether the colon is intact, whether the valve at the junction of the small and large intestines (ileocecal valve) is intact, the presence and nature of any underlying disease, and the age and overall health of the individual. Also, with appropriate rehabilitation, the remaining healthy small intestine will undergo a process of adaptation with time, and the intestinal lining may grow larger (hypertrophy) and ultimately absorb more, which may lessen an individual’s particular symptoms.
The specific therapeutic procedures and interventions for individuals with a short bowel syndrome will vary, depending upon numerous factors including the specific symptoms present, the site and extent of the affected portion of the small intestine, whether the colon is involved, an individual’s age and overall health, tolerance of certain medications or procedures, personal preference and other factors. Treatment options that may be used to treat individuals with short bowel syndrome are complex and varied. The specific treatment plan may be highly individualized and can include total parenteral nutrition (intravenous fluid and nutrition therapy), enteral feeding, dietary adjustments, oral rehydration solutions, certain medications, and/or surgery. Maintaining proper nutritional intake is vital for individuals with short bowel syndrome. In mild cases, slowly increasing the oral intake of food and taking certain supplements or medications for diarrhoea may be all that is required. However, in many cases TPN is necessary and, in severe cases, short bowel syndrome may potentially require a small bowel transplant. In recent years, advances in therapy including new options like recombinant growth hormone and glucagon-like peptide analogs and improvements in surgical techniques have lessened the length of time that individuals must remain on TPN.
Treatment for individuals with short bowel syndrome is specially designed to quicken or strengthen the process of intestinal adaption and to supply sufficient nutritional support. Intestinal adaption is the process by which the remaining or functional portion of the small bowel can adapt and increase its absorption to compensate for the missing or nonfunctioning segments. The amount of time intestinal adaption can take to occur is controversial. Originally, it was believed to occur only within six months to the loss of a portion of the small bowel. Now, many physicians believe it can occur as late as 2-3 years later. Researchers are investigating more ways to further stimulate intestinal adaption and to help the remaining small intestines to increase absorption and to function better.
After surgical removal of a portion of the small intestine, many individuals are put on TPN, which supplies all daily nutritional requirements such as protein, sugars, vitamins, minerals, trace elements and sometimes fats. TPN is a way to bypass how the body normally digests food. With TPN, a special intravenous (IV) line is inserted into a large vein and nutrients are delivered directly into the bloodstream. The first few doses of TPN are given in the hospital. Eventually, TPN can be given at home. The amount of time a person requires TPN varies. For some individuals, TPN may be a lifelong requirement. Long-term use of TPN can be associated with a variety of complications including bacterial infections, intravenous catheter complications, low bone calcium uptake, blood clots, gallbladder disease, kidney disease and liver problems. Liver and kidney problems can ultimately result in liver or kidney failure. Eventually, some individuals with short bowel syndrome will be able to discontinue TPN. Individuals may be weaned off TPN through diet, medications, and, sometimes, surgery. When intestinal function improves, affected individuals may be treated via enteral feeding. Enteral feeding is the use of a tube to deliver food directly into the stomach or small bowel. Eventually, affected individuals are given small amounts of food orally. It is important that infants receive small amounts of food orally in order for them to learn how to suck and swallow.
A variety of surgical techniques has been used to treat individuals with short bowel syndrome. Generally, surgery is used as a last resort in individuals in whom other therapeutic options have not worked. However, as surgical techniques improve, they may eventually be considered a front-line option. Surgical options for short bowel syndrome are sometimes broken down into non-transplant and transplant surgeries. Artificially lengthening the intestines has been used to treat individuals with short bowel syndrome. Two main procedures have been used the Bianchi procedure and the STEP procedure. During the Bianchi procedure, a portion of the dilated bowel is divided lengthwise into two segments. These segments are separated and joined end to end, resulting in a narrower, but a longer segment of the bowel. STEP is an acronym for serial transverse enteroplasty. This procedure is usually performed in children who have enough small bowel remaining so that surgeons can lengthen the bowel and restore function. Stricturoplasty is a procedure to widen a narrowed area of the bowel. This procedure is often done for individuals with Crohn’s disease to prevent the need for large or multiple resections of the bowel. A small bowel transplant may be an option for some individuals with short bowel syndrome, especially those who have complications from TPN such as liver failure or who were unable to maintain proper nutrition with other therapies. During a small bowel transplant, the disease small bowel is removed and replaced with one from a healthy donor. A variety of complications can occur with small bowel transplantation including organ rejection, infections, and lymphoproliferative disease. In addition, the procedure is expensive and requires the lifelong use of immunosuppressive drugs to lessen the chance of rejection. However, as surgical techniques and immunosuppressive agents improve in efficacy, survival has improved as well. Some individuals may receive a small bowel transplant along with a liver transplant (i.e., in cases with impending or frank liver failure) or other organs such as kidney or pancreas.