Irritable bowel syndrome (IBS) affects as many as one in five Americans, making it one of the most common ailments diagnosed by doctors. It's more common in women than men; and in about 50 percent of the population, it strikes before the age of 35. While symptoms can vary from person to person, the hallmarks of the disorder frequently include abdominal pain, bloating, cramping, and fluctuations between diarrhea and constipation. 

Although the specific cause of IBS is unknown, recent research is pointing to a link between the disproportionate levels of serotonin-a neurotransmitter that delivers messages from one part of the body to another-found in the gastrointestinal (GI) tract and the brain in IBS sufferers. Normally, 95 percent of the serotonin in the body is located in the gastrointestinal tract, where it's used to regulate intestinal movements, and the other five percent is located in the brain. People with IBS, however, have diminished receptor activity, causing abnormal levels of serotonin in the GI tract. This results in more pain receptors in the GI tract and more painful bowel movements.

It appears that stress, too, may contribute to symptoms of IBS as well. According to the National Institutes of Diabetes and Digestive and Kidney Diseases, stress can stimulate colon spasms in people with IBS because, like the heart and lungs, the colon is partly controlled by the autonomic nervous system. This system responds to stress and may overreact to even slight feelings of anxiety. The result can set up a vicious cycle of depression in people with IBS.

The good news for IBS sufferers is that the disorder has not been shown to lead to more serious diseases like cancer, and it is not related to Crohn's disease or ulcerative colitis. And while there is no cure for IBS, there are many options available to sufferers to treat the symptoms, including:

  • An antispasmordic to control colon muscle spasms
  • Fiber supplements or laxatives for constipation
  • Anti-diarrheal medications

Changes in your diet can help reduce the symptoms of IBS as well. To identify possible food triggers, keep a daily diary of the foods you eat and any adverse reactions you experience. Drinking six to eight glasses of water a day can alleviate diarrhea. Also, eating smaller meals that are low in fat and high in carbohydrates like pasta and whole-grain breads, fruits, and vegetables may reduce cramping and diarrhea.