A Diet for Irritable Bowel Syndrome With Diarrhea

Medically Reviewed by Arefa Cassoobhoy, MD, MPH on September 24, 2023
3 min read

Smart eating habits can make your life a little easier when you have irritable bowel syndrome with diarrhea, or IBS-D. And you don't have to completely give up any foods you like.

"Moderation is important," says Leslie Bonci, MPH, RD, author of the American Dietetic Association (ADA) Guide to Better Digestion.

It's important to stick to a balanced diet when you have IBS. So never totally avoid certain groups of food, or you may be depriving yourself of the nutrients you need.

Experiment with what you eat to find out what works for you, Bonci says. "People could be selective with what they have, saying, 'OK, I'm no good with apples, but I'm alright with a pear. Or grapes don't work for me, but I'm OK with having a little bit of a banana.'"

Keep a symptom journal to track which foods and which amounts seem to give you diarrhea. It's the best way to figure out which eats might be causing you problems. Remember, different foods affect people differently.

You could also try an elimination diet -- if you think certain foods might be triggering your symptoms, stop eating them one at a time, and see how that makes you feel.

Don't avoid fiber if you have diarrhea. It helps protect your body against heart disease, by lowering your LDL cholesterol, and certain cancers, so you need it.

Simply eat more soluble fiber, rather than the insoluble kind, Bonci says. Soluble fiber stays in the gut longer, which helps the colon work normally.

You find soluble fiber in foods such as:

  • Oats
  • Peas
  • Beans
  • Apples
  • Citrus fruits
  • Carrots
  • Barley

Insoluble fiber, on the other hand, is found in things like:

  • Whole-wheat flour
  • Wheat bran
  • Nuts
  • Beans
  • Cauliflower
  • Green beans
  • Potatoes

Although meeting your daily fiber needs is best accomplished by eating the right foods, taking a fiber supplement can also help. Examples of supplements include calcium polycarbophil, methylcellulose,  psyllium, and wheat dextrin. If you take a fiber supplement, increase the amount you take slowly to help prevent gas and cramping. It’s also important to drink enough liquids when you increase your fiber intake.

As long as your doctor has not restricted your fluids, shoot for six to eight 8-ounce glasses of plain H2O each day, but not always with meals.

"Water just makes everything run through a little more rapidly," Bonci says. She suggests you drink it an hour before or an hour after meals.

Only you know which ones give you IBS-D symptoms. But while you figure out your own triggers, you might want to take special care with foods known to cause symptoms in some people with your condition:

  • Broccoli, onions, and cabbage
  • Fried or fatty foods like French fries
  • Milk or dairy products such as cheese or ice cream
  • Alcohol
  • Caffeine in coffee, teas, and some sodas
  • Carbonated sodas
  • Chocolate
  • Gluten, found in wheat, rye, and barley

Sorbitol, a sugar substitute found in gum and mints, and fructose, a simple sugar in honey and some fruits, also trigger IBS symptoms in some people.

How you eat may also give you trouble. You might be bothered by foods with extreme temperatures, especially if you have them together, like ice-cold water with steaming hot soup. Many people get symptoms after large meals.

Try to eat less at each meal, or have four or five small meals a day.

Remember, your reactions to what you eat are unique, Bonci says. So experiment with different foods until you've come up with your own IBS nutrition prescription.

"There isn't an IBS diet, per se," Bonci says. “Some people will find they're OK with particular foods, and other people find there's just no way."