Genes may play a role in IBS. When IBS occurs in people from the same family, it may also result from similar lifestyles and shared risk factors.

IBS affects about 11% of the world’s population. For individuals with IBS, digestive pain is a frequent experience. In fact, the condition is often diagnosed based on symptoms like bloating, abdominal pain, and constipation.

Research indicates that IBS is more likely to occur if you have a biological family member with IBS, but the exact role of genes in the development of this condition is not well understood.

Although more research into IBS is still needed, here’s what is known about its genetic aspect.

Research has shown that the risk of developing IBS is twice as high if you have a biological relative with it.

In studies looking at twins, though, people were more likely to have IBS if a parent had it than if their own twin did. Less than 20% of the monozygotic twins studied both had IBS.

Single gene mutations may be responsible for some cases of IBS, but a 2016 study proposed that IBS may also stem from polygenes. Polygenes are genes with effects too small to make a noticeable difference on their own, but they can combine with other genes to have more noticeable effects.

Scientists have not yet identified specific genes that may pose a risk for IBS. One that does appear to be associated with the condition is the TNFSF15 gene, according to the same 2016 study.

A 2020 research review suggests that IBS also has an epigenetic aspect. This means that the environment and your behavior could affect the genes that determine whether IBS is triggered.

More research is still needed to better understand the involvement of specific genes in the development of IBS. Another reason why IBS may happen in members of the same family is that they may have shared similar lifestyles, as well as other risk factors.

IBS has no cure. Most of the time, treatments will focus on reducing the severity of symptoms that you experience. These symptoms can include:

  • abdominal pain
  • cramping
  • gas and bloating
  • constipation or diarrhea
  • white mucus in stools
  • feeling that bowel movements are not finished

If interested, you can learn more about IBS and its symptoms.

While IBS is present in individuals of all ages, 50% of people with IBS report symptoms before they reach 35 years old. Individuals age 50 or over are 25% less likely to report symptoms than those who are younger.

While the exact cause of IBS is still unknown, researchers and clinicians believe the symptoms an individual experiences with IBS are related to the way the brain and gut interact. It’s possible that a combination of factors may result in IBS.

Some examples of factors that may play a role in IBS are:

  • traumatic or stressful events early in life
  • bacterial infections in the digestive tract
  • food intolerances and sensitivities
  • a bacterial overgrowth from the small intestines
  • depression, anxiety, and somatic symptom disorder
  • genetics

IBS is currently diagnosed based on the symptoms that you experience.

To determine whether you have IBS, a doctor will look for a pattern of symptoms over time. They may diagnose IBS if your symptoms started at least 6 months ago or you have been experiencing symptoms at least once a week for the last 3 months.

In addition to performing a physical exam, doctors will typically ask about your family medical history to determine whether another condition may be causing painful gastrointestinal symptoms. They may also use blood and stool tests to rule out other medical conditions.

To confirm IBS, your doctor may ask for more information about how your pain is related to bowel movements and the frequency and consistency of your bowel movements. They may also ask about your lifestyle and the foods you eat.

Research indicates that a genetic component may be involved in at least some cases of IBS.

Shared lifestyles and risk factors may also help explain why IBS is more commonly seen in children if a biological parent has IBS.

Additional research in the future can help doctors better understand the role of genes in IBS.

If you believe that you may have IBS, let your doctor know, even if it doesn’t run in your family. There is currently no cure for IBS, but doctors can help create a treatment plan so you can feel relief from uncomfortable symptoms.