Diagnosing Ibs - Irritable Bowel Syndrome: Digestive Disorders

Fast fact

When introducing fiber to your diet, do so gradually. Too much, too fast can cause excessive gas, cramping, and bloating. Drink lots of water or other liquids to avoid constipation.

Irritable bowel syndrome: What else could it be?

A number of gastrointestinal diseases can cause nonspecific symptoms similar to those of IBS. Fortunately, each has its own special characteristics, which should serve as red flags to patients and doctors alike.

Diverticular disease. Small, finger-like sacs or pouches may protrude off the colon's inner lining, where the blood vessels enter the colon, piercing its walls and causing areas of weakness. Unlike polyps, which are new growths within the colon lining, these pouches, known as diverticula, are actually part of the colon.

Although the condition is most common after age 50, younger people occasionally develop diverticula. Often they cause no symptoms and the individual is unaware he or she has them. When the diverticula become inflamed or infected, the condition is called diverticulitis. The symptoms of diverticulitis are much more intense than those of IBS and include severe left lower abdominal pain, chills, fever, and an elevated white blood cell count.

When diverticula become severely inflamed, the colon can become obstructed. Even worse, its wall can be perforated, resulting in peritonitis, a potentially dangerous inflammation of the membrane lining of the abdominal cavity. The diagnosis of diverticulitis is made after a number of tests, usually including a CT scan.

Treatment of diverticulitis involves a liquid diet to let the bowel rest and antibiotic therapy to clear the infection. After the immediate infection has stabilized, patients switch to a steady high-fiber diet, to help prevent flare-ups, and are advised to avoid nuts and seeds. Surgery may be required for complicated or recurrent diverticulitis.

Inflammatory bowel disease (IBD). Inflammatory bowel disease has a wide variety of symptoms, including persistent abdominal pain, diarrhea, rectal bleeding, fever, and weight loss. Crohn's disease and ulcerative colitis, two conditions that together are referred to as inflammatory bowel disease, often have similar symptoms and are treated in similar ways, yet physicians regard them as distinct.

Some people experience periods of fairly good health interrupted by flare-ups. Others have continuous symptoms marked by serious inflammation, intestinal bleeding, and abdominal pain. The most serious consequence of IBD is colon cancer. The risk for colon cancer is much higher for patients with IBD than for the general population.

Crohn's disease can occur anywhere in the gastrointestinal tract, from the mouth to the anus, but it's usually found at the end of the small intestine (ileum), in the colon, or both. It involves the full thickness of the bowel wall and may burrow into nearby organs. The bowel wall becomes thickened as well as constantly inflamed, and leakage of intestinal contents from the bowel can cause internal abscesses. A leak (fistula) that allows intestinal material to pass into the abdomen may require surgery. Severe bleeding is not a hallmark of this disease.

Crohn's disease usually appears in young people, who develop pain in the right side of the abdomen, a low-grade fever, and perhaps changes in bowel movements. Some patients develop an abscess or fistula around the anus.

In some cases, surgery is needed to treat a complication of the disease, such as bowel obstruction. About 40%–60% of those with Crohn's eventually need surgery to remove damaged areas of their small intestine or colon.

Ulcerative colitis is characterized by inflammation of the lining, or mucosa, of the colon. Like IBS, it can cause lower abdominal pain and diarrhea. Unlike IBS, the stool generally contains blood, and bowel symptoms may be accompanied by fever, weight loss, an elevated white blood cell count, and the same non-gut manifestations as Crohn's disease. Ulcerative colitis is easier to diagnose than Crohn's disease and is treated with many of the same medications; it can even be cured because it affects only the colon, which can be surgically removed. Surgery is too drastic a treatment in most cases, but about 25% of patients eventually have surgery to remove their colons.

While drugs cannot cure IBD, they are effective in reducing inflammation and accompanying symptoms in about 80% of patients. The drugs used most commonly are aminosalicylates (cousins of aspirin), steroids (potent anti-inflammatory agents), immunosuppressants like azathioprine (Imuran), and antibiotics. Another drug, infliximab (Remicade), has proved effective for patients with Crohn's disease.

Colorectal cancer. Colorectal cancer is the third most common form of cancer in both men and women, with an estimated 145,000 new cases diagnosed in the United States each year. Early on, colon cancer causes no symptoms. Later, its symptoms can be similar to those of IBS — abdominal pain, cramping, bloating, gas pains, and a change in bowel patterns. In addition, blood in the stool or rectal bleeding is often present. Advanced cancer is likely to cause bloody bowel movements, severe constipation if the intestine is obstructed, and weight loss. Thus, it's vital to get checked without delay should these symptoms occur.

The good news is that colon cancer can be prevented in most cases through screening. Almost all precancerous growths (polyps) can be spotted and removed during a colonoscopy. Early stage, localized colon cancers are curable by surgery in 90% of cases. To catch polyps or early cancer, the American Cancer Society recommends that, beginning at age 50, men and women should have one of the following: an annual fecal occult blood test (FOBT) plus flexible sigmoidoscopy every 5 years, or a colonoscopy every 10 years, or a double-contrast barium enema every 5 years.

"Virtual colonoscopy" — in which a CT scanner that is completely outside the body takes hundreds of wafer-thin pictures of the inside of your colon and rectum that a computer then assembles into a complete image — is available as a potential alternative to conventional colonoscopy. However, studies so far have offered conflicting results on whether the newer method, also known as CT colonography, detects polyps effectively enough to take the place of standard colonoscopy. The disadvantage of virtual colonoscopy is that if a polyp is found, you will need to undergo a standard colonoscopy to remove it.

Celiac disease. Also known as celiac sprue, celiac disease is a genetically based disorder that damages the small intestine and may result in debilitating symptoms. As many as one million Americans may have the disease, which clusters in families, primarily occurring in whites of European ancestry. It often goes undiagnosed.

When people with celiac disease eat foods containing gluten — a protein found in wheat, rye, and barley — their immune systems attack and destroy the tiny finger-like projections lining the small intestine. Many patients have no symptoms. In others, symptoms may include abdominal discomfort and gas, persistent diarrhea, weight loss, and bone pain. In severe cases, patients also can develop anemia, malnutrition, and osteoporosis. A simple blood test for higher-than-normal levels of antibodies to transglutaminase, an enzyme in the gut that processes gluten, is the first step in diagnosing the disease. If the test is positive, a biopsy of the small intestine, performed through a standard endoscope, can confirm the diagnosis. Treatment is straightforward: a gluten-free diet. Symptoms often improve within days, and the small intestine gradually returns to normal function.

Understanding food intolerance

Food intolerance and allergies often produce similar symptoms, but they're not the same. A food allergy is an abnormal response to a food by the immune system. Food intolerance, on the other hand, doesn't involve the immune system, but rather some other dysfunction, such as inadequate amounts of an enzyme needed to digest a particular type of food.

For some people, heartburn, gas, nausea, upper abdominal stomach upset, diarrhea, cramps, and flatulence — all common symptoms of functional disorders — may be caused by a food that simply doesn't agree with them. The problem isn't that the food is spoiled, unripe, or contaminated by bacteria, but that the body is unable to digest a particular substance. The best-known problem of this sort is lactose intolerance, a difficulty in digesting dairy products. It's been estimated that up to 70% of the world's population has a problem with lactose, though it's minor for most. Lactose intolerance is more prevalent in certain ethnic groups, including Jews, African Americans, Native Americans, and Asians. People who are lactose intolerant are unable to digest large quantities of lactose, the primary sugar in milk. The problem occurs when there's a shortage of the enzyme lactase, which breaks down milk sugar into simpler forms that can be absorbed by the bloodstream.

Typically, early symptoms appear about 30 minutes after consuming dairy products. You may develop gas, diarrhea, bloating, cramps, or nausea. The symptoms represent a direct chemical toxic effect (unlike a food allergy, which involves the immune system and can have more serious consequences, including allergic shock).

The best way to avoid the symptoms of lactose intolerance is to avoid dairy products. But if you don't wish to make that concession, you can add a special enzyme preparation to them with products such as Lactaid. There are now milks, yogurts, and ice creams that already contain the enzyme. Some people prefer to take Lactaid tablets before eating dairy products. Others who don't have as severe a problem may find that they can eat some dairy products as long as they consume them with other foods. Yogurt may not cause as many problems as other dairy products, probably because it is fermented. Alternatives to dairy include soy- or rice-based products, which are available in health food stores and many supermarkets.

On the other hand, many foods contain hidden dairy products. Be sure to read the labels on breads, processed breakfast cereals, instant potatoes, soups, margarine, lunch meats, salad dressings, pancake mixes, and similar products; check the ingredients list not only for milk, but also for whey. Nondairy kosher foods are a safe bet, however, since kosher laws mandate that these foods cannot contain any milk products.

Another food intolerance centers on difficulties in digesting wheat or substances that contain the wheat protein called gluten. This protein is found in foods containing wheat, rye, and barley. Ingesting gluten can cause bloating, gas, abdominal distention, and diarrhea. Avoiding gluten-containing products will eliminate the problem. Gluten intolerance is distinct from celiac disease, which is an immunological reaction to gluten.