No one knows exactly what causes IBS. Indeed, the symptoms of IBS are normal reactions that many people experience for a number of different reasons. Unfortunately for those with IBS, these symptoms occur with more frequency and, usually, more severity. What medical professionals don’t understand is why these symptoms occur more often in some people than in others.

Factors that aggravate IBS may include:

Diet : Food intolerance or sensitivity to certain foods may aggravate symptoms of IBS. Fatty foods, dairy products, chocolates, coffee, alcohol, carbonated drinks and artificial sweeteners all may worsen episodes. Meats, large meals and meals that are eaten too quickly can also make the digestive system work too hard. Gluten, a protein found in wheat and barley, is one of the most common triggers of IBS.

Chemical imbalance : Some medical professionals believe that an imbalance of the neurotransmitter serotonin may make IBS symptoms worse. Although serotonin is typically associated with brain function, particularly with clinical depression, only five percent of the body’s serotonin is in the brain; the other 95 percent is in the gut. The gut is filled with nerve endings. If too much serotonin is present in the colon, these nerve endings become too sensitive, leading to excessive pain.

Age and gender : For unknown reasons, women are up to four times more likely than men to suffer from IBS. IBS symptoms may co-exist with pre-menstrual or menstrual symptoms. Perhaps nearly a quarter of all women in the U.S. suffer from IBS. The syndrome is also more prevalent in younger people. Onset typically occurs before the age of 35.

Other illnesses : IBS symptoms can occur or worsen after a bout with other intestinal illnesses. Sufferers from the “stomach flu,” or gastroenteritis, sometimes go on to struggle with IBS. A number of bacteria or viruses can cause gastroenteritis; among the most well-known are Salmonella, E. coli, norovirus and rotavirus.

Learn about IBS – Irritable Bowel Syndrome Foods, and common Irritable Bowel Syndrome Treatments.