Irritable bowel syndrome (IBS) affects up to one in five of us, and young women are most likely to experience it. We spoke with Stephanie Gapper, R.N., a nurse at OHSU's Digestive Health Center, to find out what you need to know about IBS and how to manage it. 

What is IBS? 

Stephanie: IBS is a condition affecting the gastrointestinal tract. It is caused by a change in gut-brain communication, leading to symptoms like abdominal pain, bloating, diarrhea or constipation, or urgency to have a bowel movement. 

Is IBS different for women? 

Stephanie: We know it affects more women than men;about twice as many women. Some women have more IBS symptoms at the beginning of their period each cycle, due to hormonal changes. IBS with constipation, or with alternating constipation and diarrhea, is more common in women than in men. 

How is IBS diagnosed? 

Stephanie: People with IBS can be frustrated with this process. They continue to have symptoms, but tests, like colonoscopy or MRI, show that everything is normal. This doesn't mean that IBS is a "diagnosis of exclusion" [a diagnosis given when every other possible cause isn't the answer] though! IBS is caused by a change in the brain-gut connection, not by visible problems in the body. To be diagnosed with IBS, you must have abdominal pain at least once a week, on average, accompanied by a change in frequency or appearance of your stool. 

IBS and IBD are similar acronyms. How different are they? 

Stephanie: They cause some similar symptoms, like abdominal pain and changes in bowel movements, but the underlying causes are very different. 

IBD is inflammatory bowel disease. This is an autoimmune disease—the immune system is attacking the gastrointestinal tract. The treatments for IBD are also very different. 

How is IBS treated? 

Stephanie: Treatment of IBS is very individualized, and depends on your symptoms. Common treatments include looking at how to reduce stress, dietary changes, cognitive behavioral therapy, and medication. 

Keeping a food diary can help you determine if your body is sensitive to certain foods. IBS is not a food allergy, but specific foods can often trigger IBS symptoms. A low FODMAP diet is often helpful for IBS patients. It limits certain types of carbohydrates that can be harder to digest, leading to symptoms.