Digestive Health Irritable Bowel Syndrome Causes & Diagnosis Is Irritable Bowel Syndrome (IBS) Hereditary? By Amber J. Tresca Updated on February 07, 2024 Medically reviewed by Jay N. Yepuri, MD Print Table of Contents View All Table of Contents IBS in Families Age IBS Appears What Causes IBS? Genetic Testing When to See a Provider Irritable bowel syndrome (IBS) tends to run in families, but whether that is from shared lifestyle factors, genetics, or both is not well understood. IBS is a common gastrointestinal condition that affects between 10% and 25% of people in the United States and is associated with decreased quality of life. It causes symptoms such as abdominal pain and changes in bowel habits (diarrhea and/or constipation). This article will look into the evidence so far about how IBS may be related to genetics and who may be more likely to develop the disorder based on age and sex. FG Trade / Getty Images Can IBS Be Passed Down Within Families? People with IBS tend to be more likely to have family members who also live with the condition. People living in the same household or who are related are exposed to similar environments, dietary patterns, and lifestyle factors. Whether IBS arises from these common familial factors or genes has been the subject of some studies, but it is still unclear. Some research has examined how much genes and environment play a role in developing IBS. A nationwide study in Sweden showed that some cases of IBS are closely related to genetics. A higher risk for IBS was found in families in up to third-degree relatives. Third-degree relatives include great-grandparents, great-grandchildren, granduncles, grandaunts, first cousins, half-uncles, half-aunts, half-nieces, and half-nephews. It’s now thought that at least 60 genes increase the risk of developing IBS. However, the studies so far haven’t been strong enough to narrow down how the genes interact. It’s also not known yet which of these genes may put someone at a higher risk than others. Research shows that people are more likely to be diagnosed with IBS when they have a full- or half-sibling with the condition. IBS can also be diagnosed in children. One study found that about 5% of kids over age 4 meet the criteria for IBS. What Age Does IBS Typically Appear? IBS could be diagnosed in anyone of any age and in any part of the world. However, some groups may be more likely to develop the signs and symptoms of IBS. IBS tends to be more common in women than it is in men in most parts of the world. IBS is more commonly diagnosed in adults (people aged 18 or over) than it is in children or teens. One broad study showed that 90% of those who met the criteria for a diagnosis of IBS were adults. It was also shown that in Western countries, the age at diagnosis was more likely to be between 20 and 40 years. The studies from Taiwan showed that older age was another risk factor. Looking at the data about who has IBS symptoms, researchers speculated that people may be living with it, probably on and off, for 25 years of their lives. A Note on Gender and Sex Terminology Verywell Health acknowledges that sex and gender are related concepts, but they are not the same. To reflect our sources accurately, this article uses terms like “female,” “male,” “woman,” and “man” as the sources use them. What Causes IBS? IBS is now often called a disorder of the brain-gut axis, which means that the brain and the gut interact in a way that leads to the signs and symptoms. There may be many potential causes of IBS. More than one factor is likely at work in any person with the signs and symptoms. There could also be a genetic component. The genes may be expressed when another factor comes into play. IBS is increasingly being understood to be a complex condition with many potential causes. Some of the potential contributors to the development of IBS are thought to be: Changes in the gut (microbiome, motility, and permeability) Changes in the immune system Diet Exposure to stressful life events at a young age Genetics Hypersensitivity to pain Infection that affects the digestive system (gastroenteritis) Having other gastrointestinal conditions (such as inflammatory bowel disease or celiac disease) Mood disorders (anxiety and stress) Treatment with antibiotics People with IBS may find that various foods and/or life events, such as stress, bring on symptoms like diarrhea or urgency. Over time, it may become clear what triggers bring on symptoms of the condition. They tend to be different for each person. Work with a healthcare provider to identify triggers and learn ways to reduce your exposure to them. Can Genetic Testing Help Diagnose IBS? The genetics of IBS, and indeed for many conditions, is still being uncovered. Studies on the genetics of IBS have provided information, but they have been small. Not enough is known yet about which genes might be most important. No genetic tests are available at this time that can detect a higher risk of developing IBS. Genetic testing is done only in the setting of a clinical trial. Even then, the criteria for diagnosing IBS will be used; the genetic testing results may not provide any information that can be acted upon. When to Contact a Healthcare Provider People who are experiencing symptoms of IBS should let their healthcare provider know when the symptoms started. Keeping a food and symptom diary can help detect patterns. Some of the symptoms of IBS can include: Abdominal pain or cramps A mix of diarrhea and constipation Bloating or distention Constipation Diarrhea Feeling the need to move the bowels, but nothing comes out Urgent need to go to the bathroom Some symptoms are not considered part of IBS. These symptoms should prompt a person to seek care right away because there may be another reason for them beyond an irritable bowel: Bloody stools Getting up at night to use the bathroom Iron deficiency (as shown by a blood test) Unexplained weight loss Summary The understanding of what may cause IBS has undergone some significant improvements in recent years. Many questions are unanswered, but the accepted idea is that IBS is a complex disorder and not one that’s caused only by diet or stress. How much of IBS is genetic, which genes are connected to the disorder, and how it may be inherited are active areas of study. Gene testing is not currently available for the genes possibly connected to IBS. People experiencing digestion problems should seek care from their healthcare provider to get a diagnosis and recommendations on treatment. 11 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. 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JAMA. 2015;313(9):982. doi:10.1001/jama.2015.0958 By Amber J. Tresca Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit