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Irritable Bowel Syndrome

Contributors: Esther Ellis, MS, RDN, LDN

Reviewers: Academy Nutrition Information Services Team

Published: April 12, 2022

Reviewed: February 19, 2024

Irritable Bowel Syndrome

Irritable bowel syndrome, or IBS, is a chronic or reoccurring series of gastrointestinal symptoms that often causes distress for those who have it. IBS is associated with a group of symptoms that affect the large and small intestines. It is estimated that IBS affects 10% to 15% of adults worldwide. Though no specific cause is known, several factors may contribute to IBS, including genetics, certain mental health disorders, food sensitivities or intolerances, infection or a change in intestinal bacteria type or amount. Certain foods and stress may trigger symptoms; diet changes, stress management and a healthy, active lifestyle may help manage IBS.

Symptoms of IBS

Symptoms vary, but typically include one or more of the following:

  • Abdominal pain
  • Cramping
  • Constipation or diarrhea
  • Bloating
  • Gassiness

Your doctor may order medical tests to rule out other causes of these symptoms.

IBS Triggers

People with irritable bowel syndrome have a sensitive intestinal tract in which stress and diet may play a role.

  • Stress. The colon contains nerves that connect to the brain. For people with IBS, stress can stimulate spasms in the colon, causing discomfort and pain.
  • Diet. Some people with IBS find symptoms worsen after eating large meals or high-fat foods. Specific foods also may trigger symptoms and can vary from person to person.

Changes for the Better

The best way to manage IBS can be highly individualized. It’s important to understand what may cause episodes of discomfort and then work to eliminate or minimize them. While medication, stress management and probiotics may help, eating habits also should be a focus, because they can have a significant impact. Some simple changes in the way you eat may offer relief and reduce future flare-ups.

  • Establish regular eating habits. Eating your meals at the same time each day may help regulate your bowels.
  • Eat small, frequent meals instead of large ones. This will ease the amount of food moving through your intestinal tract.
  • Focus on a healthful eating pattern, including sources of dietary fiber. Try whole fruits, vegetables, beans and whole grains including rolled oats, brown rice and whole-wheat bread. Make changes slowly. Fiber helps move food through your intestine, but it takes time for your body to adjust to eating more. Adding too much too quickly may result in gas, bloating and cramping.
  • Drink enough fluids. Fiber draws water from your body to move foods through your intestine. Without enough water and fluids, you may become constipated.
  • Watch what you drink. Alcohol and caffeine can stimulate your intestines, which may cause diarrhea. Artificial sweeteners that contain sugar alcohols such as sorbitol, mannitol and xylitol may cause diarrhea too. Carbonated drinks can produce gas.
  • Consider FODMAPs. Fermentable, oligosaccharides, disaccharides, monosaccharides and polyols — these short-chain carbohydrates are found naturally in many of the foods we eat. They may be poorly absorbed in the intestine by people with IBS. A registered dietitian nutritionist can help determine if there are high-FODMAP foods you may be sensitive to and if a modified eating pattern is right for you.
  • Identify problem foods and eating habits. Recording your daily food intake in a food diary during flare-ups can help you figure out which foods contribute to IBS symptoms.

How an RDN Can Help

A registered dietitian nutritionist can help you manage irritable bowel syndrome by developing an individualized eating plan. An RDN will work with you to identify which foods and habits might cause you distress and review healthy eating strategies to help you manage your symptoms, along with other forms of treatment, if needed.

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