Why Do I Have IBS?

4 IBS causes and solutions

Among the many factors that may lead to IBS:

1. Infection

About 1 in 10 people develop IBS after a bout of gastroenteritis, a.k.a. the stomach bug, explains Yuying Luo, M.D., a gastroenterologist at Mount Sinai Center for GI Physiology and Motility in New York City. Food poisoning can also trigger an inflammatory response in your GI tract.

What you can do: Research results are mixed but suggest that some probiotic strains may improve IBS symptoms, including bloating and gas. The probiotic Bifidobacterium bifidum MIMBb75 has been shown in clinical trials to alleviate IBS symptoms. A 2022 review of studies found that strains of another probiotic, Bacillus coagulans, also significantly helped to improve symptoms.

2. Food sensitivities

“As we age, we have less enzymes to break down disaccharides, a type of sugar found in carbohydrates,” Lembo explains. A 2020 study of patients with IBS symptoms found that about half had a disaccharidase deficiency. Ultraprocessed foods, which include multiple chemical additives, can exacerbate symptoms, Luo adds.

What you can do: Your doctor may suggest that you try what’s called a low-FODMAP diet. This is a diet that, under medical supervision, reduces foods that some people find hard to digest, including certain fruits and veggies, dairy, beans and some grains and nuts. Typically, you follow this elimination diet for two to four weeks, then gradually add these foods back in under the guidance of your doctor. Luo also recommends patients try a Mediterranean diet — with lots of vegetables, fish and olive oil — and avoid processed foods.

3. Genetics

You’re two to three times more likely to develop IBS if it’s part of your family history, Chey says. Researchers in a 2021 study found six gene mutations that raise the risk of IBS; they also found that the same genetic makeup increases the risk for depression and anxiety. “It makes sense, since we know IBS involves both your brain and your gut,” Chey says.

What you can do: The first step is usually to make dietary changes — a low-FODMAP diet, for instance. If that isn’t enough, a laxative or antispasmodic may be prescribed. Tricyclic antidepressants such as nortriptyline (Pamelor) and desipramine (Norpramin) can help with abdominal pain and symptoms of diarrhea by slowing your GI tract.

4. Emotional trauma

“A lot of research suggests that abuse or trauma early in life raises the risk to develop IBS later on,” says Douglas Drossman, M.D., founder and CEO of the Rome Foundation, a nonprofit organization dedicated to education and research on disorders including IBS. Drossman’s research looked at the brain MRIs of abuse survivors with irritable bowel syndrome and found that the part of their brain that controls pain doesn’t work as well as it does in people who have IBS alone.

What you can do: Behavior interventions can help to manage symptoms, especially if yours stem from stress or trauma, says Frank Sileo, a psychologist in Ridgewood, New Jersey. These include:

• Cognitive behavioral therapy (CBT). This is a type of talk therapy that works to change how you react to certain situations.
• Hypnosis. More than 30 published research studies show this treatment can help ease the symptoms of IBS.
• Mahana IBS, a prescription-only digital CBT treatment that’s been cleared by the Food and Drug Administration.

Whatever the cause of your IBS, most people find relief through a combination of dietary changes, behavioral techniques and sometimes medications, Chey says.