Diarrhea-predominant irritable bowel syndrome (IBS-D) is a subtype of IBS in which a person experiences frequent bouts of diarrhea accompanied by abdominal pain. Like IBS, IBS-D is a functional gastrointestinal disorder (FGD) in which there is no visible disease, inflammation, or injury to explain its symptoms. It is estimated that around a third of people with IBS experience diarrhea as the predominant symptom.
Unlike other subtypes of IBS, people with IBS-D often experience:
Additionally, people with IBS-D also have some or all of the following IBS symptoms:
According to the Rome IV diagnostic criteria for IBS, symptoms should occur on average at least once a week for at least three months.
Some people with IBS may find that they switch from IBS-D to periods of constipation-predominant IBS (IBS-C).
Others regularly alternate between constipation and diarrhea, which is a subtype known as mixed-type IBS (IBS-M) or alternate-type IBS (IBS-A).
Although the exact cause of IBS-D is unknown, researchers are investigating several different possibilities. This includes:
If you think you may have IBS-D, make an appointment with your doctor. There are other serious medical conditions that have many of the same symptoms as IBS-D. This must be ruled out.
If your healthcare provider concludes that you have IBS-D, they will work with you on a treatment plan. They may recommend over-the-counter treatments or prescribe medications. The options include:
Additionally, the American College of Gastroenterology recommends that all IBS patients try a low-FODMAP diet to see if it helps relieve symptoms. IBS-D symptoms can also improve with other dietary changes, such as:
- Eat small meals
- Avoid fatty foods
- Avoid fried foods
- Keep a food diary
- Identify and avoid foods that cause irritable bowel syndrome