What is a good diet for IBS?

Finding the right diet can help ease IBS symptoms, but there’s no such thing as one-size-fits-all.

Healthy foods on cutting board

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If you’ve been diagnosed with Irritable Bowel Syndrome (IBS), it may seem daunting to figure out what you can eat that doesn’t aggravate your condition. But your diet can make a major impact on how you feel and help you manage your symptoms. In fact, one of the most common questions for doctors is what food to avoid.

What is IBS?

Irritable Bowel Syndrome is a disorder in which patients experience abdominal pain and discomfort along with bowel problems and a range of symptoms. These symptoms include diarrhea, constipation, gas and bloating.

According to the International Foundation for Functional Gastrointestinal Disorders, IBS affects 25 to 45 million people in the US. Most people who have IBS are under the age of 50.

What causes IBS?

It’s unclear exactly what causes IBS. In some patients, contractions in the intestines may be faster or slower, causing different reactions in different people. According to the Mayo Clinic, some people with IBS have abnormal levels of serotonin, which can play a role in digestion. There are also theories that people with IBS do not have the right balance of good bacteria in their intestines.

But IBS does have know triggers that can aggravate symptoms. These include:

  1. Stress
    If you are feeling particularly stressed, your IBS symptoms may worsen.
  2. Hormones
    Some women find their IBS symptoms are worse during the time around their menstrual periods.
  3. Foods
    Some people find that their symptoms worsen after a meal with certain foods.

Can diet control IBS?

Dr. Todd Sheer, gastroenterologist at The Austin Diagnostic Clinic, says it is possible to control IBS with diet alone in some, but not all, patients.

But there’s no one-size-fits-all diet. The recommended diet is based largely on the patient’s symptoms, and depending on the severity of the condition, diet will be used in conjunction with medication therapy, probiotics and even stress management.

“For constipation predominant IBS, I recommend a higher fiber diet (25 grams per day for women and 30 grams per day for men),” Dr. Sheer said. “I caution patients not to ‘overdo’ it on the fiber as this can often make symptoms worse.  For those with diarrhea and/or bloating as the predominant complaint, reducing or even eliminating the intake of FODMAPs helps tremendously.”

Are there certain foods that aggravate the digestive system?

Purvi Desai, registered dietitian and certified diabetes educator with ADC, says some food groups do tend to aggravate IBS more than others.  In many patients, these are gas-forming foods, such as cabbage, Brussels sprouts, broccoli and dried beans.

“Remember that IBS is very individualistic, but it does seem that dairy, alcohol, caffeine and foods very high in fat cause more discomfort,” Desai said. “I recommend they start keeping a food journal and write down the ‘trigger foods.’ Especially take note of what food was eaten, how much and the symptoms that followed. Also, note if that time was a more stressful time.  Work on having smaller, low-fat meals versus a very large meal.”

What is the FODMAP Diet?

Dr. Sheer says FODMAPs are highly fermentable foods that are metabolized by the colonic bacteria into byproducts which worsen IBS symptoms.

Examples of FODMAP-rich foods are:

  • Fructose-containing foods (apples, pears, honey)
  • Lactose-containing foods (milk, ice cream, certain cheeses)
  • Fructan-containing foods (asparagus, onions, broccoli, wheat)
  • Polyol-containing foods (artificial sweeteners (often ending in -ol), watermelon, mushrooms)

The FODMAP diet (fermentable, oligosaccharides, disaccharides, monosaccharides, and polyols) can help relieve the symptoms of IBS and identify the ‘trigger foods’ that may be causing the discomfort.

There are many comprehensive lists with the full FODMAP list on the internet and there is even a smartphone app to help remember.

“Despite the popularity of “gluten-free” diets, it is unclear if gluten is the culprit,” Dr. Sheer said. “Furthermore, I suggest having celiac testing done before embarking on this type of diet and in all patients with chronic diarrhea.”

While there is no one-size-fits-all diet for patients with IBS, visiting a physician and dietitian may help you find the foods that cause your symptoms so you can avoid them and enjoy the foods you can tolerate.