Doctors don’t know for sure what causes irritable bowel syndrome, but some things seem to make people more likely to have it than others. These risk factors for IBS include:
Being a woman. About twice as many women as men have the condition. It’s not clear why, but some researchers think the changing hormones in the menstrual cycle may have something to do with it.
Age. IBS can affect people of all ages, but it's more likely for people in their teens through their 40s.
Family history. The condition seems to run in families. Some studies have shown that your genes may play a role.
Emotional trouble. Some people with IBS seem to have trouble with stress, have a mental disorder, or have been through a traumatic event in their lives, such as sexual abuse or domestic violence.
It's not clear what comes first -- the stress or the IBS. But there's evidence that stress management and behavioral therapy can help relieve symptoms in some people with the condition.
Food sensitivities. Some people may have digestive systems that rumble angrily when they eat dairy, wheat, a sugar in fruits called fructose, or the sugar substitute sorbitol. Fatty foods, carbonated drinks, and alcohol can also upset digestion.
There's no proof any of these foods cause IBS, but they may trigger symptoms.
Large meals, or eating while you do something stressful, like driving or working. Again, these activities don’t cause irritable bowel syndrome, but for those with a very sensitive colon, they can spell trouble.
Other digestive problems, like stomach flu, traveler's diarrhea or food poisoning. Some scientists think these illnesses may trigger a person’s first IBS symptoms. Post-infectious IBS occurs in up to 32% of people who've had a bout of acute stomach flu. Symptoms like abdominal discomfort and diarrhea can last 2-3 years.
Talk to your doctor if you think you might have irritable bowel syndrome. They can discuss your symptoms with you and do some tests to find out what’s going on.