Irritable Bowel Syndrome

Contributors: Esther Ellis, MS, RDN, LDN
Irritable Bowel Syndrome


Irritable bowel syndrome, or IBS, is a chronic or intermittent disorder of gastrointestinal functioning. 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. Though no specific cause is known, several factors may contribute to IBS, including genetics, lifestyle, allergies, 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 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.


People with IBS 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 may also trigger symptoms and can vary from person to person.

Changes for the Better

The best way to manage IBS is to understand what may cause episodes of discomfort and then work to eliminate or minimize them. While medication, stress management and probiotics may help, diet and eating habits should be a focus, because both can have significant impact. Simple changes in your diet can 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.
  • Eat fiber-rich foods. 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, draw extra water into the intestine and are rapidly fermented by bacteria in the gut. An RDN can help you learn more about following a low FODMAP diet.
  • 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.

Tap Into a Great Resource

A registered dietitian nutritionist can help you manage IBS through diet. An RDN will work with you to identify which foods and habits might cause trouble and you will learn healthy eating strategies to reduce the risk of pain.

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