The small intestine (see Figure 1) is the major site for the digestion (breakdown of nutrients from food and liquid) and absorption (passage into the bloodstream) of nutrients so they can be used by the body. The small intestine is about 10 feet long, starts at the end of the stomach and continues until it empties into the colon or large intestine. It is divided into three parts. The first section is the duodenum (approximately 12-18" in length) and is followed by the jejunum and then the ileum. In the duodenum, the acid mixed with the food delivered from the stomach is neutralized by water and bicarbonate that is secreted by the pancreas. This is important because the digestive enzymes and processes of digestion in the small bowel occur in a neutral, not acidic, environment.

INTESTINAL DISORDERS

Duodenal Ulcer, Peptic Ulcer Disease

What is the cause of ulcers? At least 70 percent of ulcers are due to chronic infection of the stomach by a bacterium called Helicobacter Pylori. This infection usually occurs during childhood, but the ulcers don't develop until years later. Not all people infected with Helicobacter Pylori develop ulcers. With proper medical treatment, the infection can be eliminated in most patients. Once the infection is cured, the chance of having another ulcer is a very small. Other patients who develop ulcers usually have been regularly taking medications called NSAIDs (non-steroidal anti-inflammatory drugs). Examples of these medications are aspirin and other commonly medications used to control pain or to treat arthritis symptoms, such as: ibuprofen, naproxen sodium ketoprofen, etc.

The symptoms caused by an ulcer may be pain when the stomach is empty (often relieved when food an antacid is ingested), nausea, vomiting or digested blood in the stool (bowel movement). The stool would appear black, sticky and have a foul odor. If bleeding occurs, one should consult his physician immediately! Most ulcers can be treated medically with a variety of medications. Surgery is indicated for any of the four following reasons:

• Intractable pain - pain uncontrollable with medication.
• Obstruction - scar tissue associated with the ulcer that has caused a narrowing of the small intestine.
• Hemorrhage - bleeding, which cannot be controlled, except by surgery.
• Perforation - the ulcer has penetrated through the wall of the small intestine causing leakage of the contents into the abdominal cavity.

Lactose Intolerance

Lactose intolerance is a common problem. It can occur in 20% of Caucasians, 50% of Hispanics, and up to 70% of African Americans.

Lactose is a sugar found primarily in dairy products (milk, cheese, ice cream). It is normally digested by the enzyme, lactase, which is found on the surface lining of the small intestine. The products of digestion, glucose and galactose, are then absorbed into the bloodstream.

Lactose intolerance occurs when the intestine cannot digest lactose. The most common issue is that of low lactase levels. Lactase activity decreases with age and can be lower in certain ethnic groups such as Hispanics and African Americans. Less common causes are: congenital lactase deficiency and malabsorption caused by diseases of the small intestine (sprue, bacterial overgrowth).

Some people have little or no symptoms. Their colon is able to adjust and deal with the lactose. Many people, however, can be quite symptomatic. Common symptoms include: abdominal pain, bloating, flatulence, and diarrhea. Vomiting is unusual. Pain is often crampy and located in the lower abdomen. Stools can be loose, frothy, or watery.

The diagnosis of lactose intolerance is made through a combination of history, physical exam, and testing. Tests may include stool studies or the more specific lactose hydrogen breath test. Another practical "test" is to avoid all dietary lactose for a period of time and monitor the symptoms.

Treatment of lactose intolerance includes three general approaches:

1) Lactose restriction - The major dietary sources of lactose are milk, ice cream, and cheese. Initially all are eliminated. However, most people can tolerate small amounts of lactose and small amounts of dairy products can be reintroduced over time.

2) Enzyme replacement - One option is to take synthetic lactase. There are multiple commercially available products. Some are pills taken with meals and some are liquid which is actually added to the food (milk, for example). Doses would vary from person to person.

3) Calcium supplementation - Dairy products are the main source of dietary calcium. Restriction of dairy products can lead to inadequate calcium intake and predisposition to conditions such as osteoporosis. For this reason, people with lactose intolerance should also take a calcium supplement (such as Tums).

Sprue, Celiac Disease, Gluten Enteropathy

A rather rare condition in which the small intestinal cells are sensitive to a substance called gluten, which is contained in wheat, barley, rye, and oats. Consumption of gluten causes damage to the lining of the small intestine and consequently prevents adequate absorption and digestion of the nutrients. Symptoms include abdominal pain, cramps, gas, bloating, and diarrhea with weight loss. The treatment is a gluten-free diet.

Crohn's Disease, Regional Enteritis

Named for Dr. Burrell Crohn who first described the condition, it is a disease of unknown cause that can affect any part of the intestinal tract from the mouth to the anus. It most commonly affects the last few inches of the small intestine (the terminal ileum). It may affect this area alone or in combination with other segments of the small intestine or colon. The disease process results in ulceration of the lining of the intestine. The ulcers may become deep and actually erode through the bowel between loops of bowel, from the bowel into the urinary bladder or vagina or out the abdominal wall. Symptoms of Crohn's disease include abdominal pain, cramps, distention, and diarrhea often associated with weight loss. Medical treatment usually sufficient to control the disease and will heal the ulceration present in the bowel. If medical treatment is unsuccessful or if a fistula had developed, surgery may be necessary to remove a segment of the diseased bowel. Many patients with Crohn's disease have involvement of the anus. This can result in scarring and narrowing of the anus. Sometimes fistulas can start in the rectum or anus and exit through the skin near the anus.

Traveler's Diarrhea, Turista

Patients who travel outside the United States, particularly to Mexico or the Third World countries, are very prone to develop traveler's diarrhea. A microorganism call E. coli often causes this. Everyone has E. coli in the intestinal tract. However, the type of E. coli we have varies from that of people who live in other countries. It is not unusual to develop diarrhea when traveling abroad. If you are going to be traveling for a short time, medications are available that can significantly reduce your chances of developing this problem, and you should discuss this with your doctor before you leave. The symptoms frequently experienced are intense abdominal cramps, sometimes with fever and watery diarrhea.