What causes IBD?

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    Last Updated: May 16, 2025

    The exact causes of inflammatory bowel disease (IBD) are unknown, but it is thought to result from interactions among the immune system, genetics, gut microbiome, and lifestyle factors. Risk factors include smoking, certain medications, female hormones, infections, and other autoimmune diseases.

    The exact causes of IBD are unknown, but researchers suspect that these diseases result from interactions between the immune system, genes, gut microbiome, and certain lifestyle factors. IBD is thought to be an autoimmune reaction, and genetics likely play a role since it tends to run in families.

    Smoking, certain medications, female hormones, infections, and the presence of other autoimmune diseases may slightly increase the chances of developing IBD.[1] [2] [3]