IBS has a strong genetic component, and genetic studies have suggested that the heritability of IBS (the degree to which this condition is due to genetic factors) may be between 22–57%.[1] Individuals who have a relative with IBS are 2–3 times more likely to have IBS.[1] A study found that women with IBS-D had a gene mutation that affected serotonin receptors in the gut. Since gut-derived serotonin helps regulate intestinal motility, this could explain some IBS symptoms.[2] While hundreds of genetic variants have been studied for their potential role in IBS, to date, no single gene has been identified as playing a major role in IBS, though research is ongoing.
What is the role of genetics in IBS?
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•Last Updated: May 16, 2025
Irritable bowel syndrome has a significant genetic component, and heritability estimates range from 22% to 57%; individuals with a family history of IBS are 2 to 3 times more likely to develop the condition. Although many genetic variants have been studied, no single gene has been definitively associated with IBS, though ongoing research continues in this area.