One of the things that struck me about irritable bowel syndrome (IBS) is how very common it is. While gathering information for "Bowels in an Uproar," I learned that half-a-dozen of my friends and acquaintances have been diagnosed with it.
But I also learned that IBS is just one of a host of motility disorders, or illnesses that impair the normal stretching and contracting of the muscles lining the digestive tract. With 30 feet of tubing and compartments in the gastrointestinal tract, there is a lot of opportunity for glitches. Hopkins gastroenterologist Marvin Schuster listed just a few for me, starting from the top of the system and working down.
In certain swallowing disorders, the sphincter leading to the esophagus becomes paralyzed. Patients cannot swallow properly, and risk choking. Treatment involves learning new ways of swallowing to avoid choking. The most common cause of these disorders is stroke.
A condition called diffuse esophageal spasm can lead patients to believe (mistakenly) that they are having a heart attack. The real cause of their pain is spasms in the muscles lining the esophagus.
In gastroesophageal reflux, the sphincter at the base of the esophagus does not contract sufficiently, which allows the stomach's contents to seep or even flow full force into the esophagus. The illness causes heartburn and, in severe cases, vomiting.
Gastroparesis, or partial paralysis of the stomach, occurs in 40 to 50 percent of type II diabetics, according to Schuster.
Patients with a rare disorder called chronic intestinal pseudoobstruction (CIP) have chronic constipation and abdominal pain--symptoms that appear to be signs of an intestinal blockage. But there is no blockage, and in many cases, the cause of the illness remains unknown. Adding to the mystery, Schuster discovered that half of CIP patients have an unusual fingerprint pattern seen in fewer than 10 percent of the general population.
Not all functional digestive problems are rare. The list also includes diarrhea and constipation, which involve impaired motility of the colon. About 2.5 million Americans each year see a doctor for constipation, according to the International Foundation for Bowel Dysfunction. Americans spend more than $350 million each year on over-the-counter laxatives.
Finally, the sphincters that allow for continence can become impaired, as a result of a variety of illness and injuries including various neuromuscular disorders, operations, tears during childbirth, and diabetes. Many of these patients can regain control through biofeedback, which involves learning how to contract the sphincters at the right time.