Peeled vegetables such as zucchini and squash can be incorporated into an ulcerative colitis diet.

What to eat, what to avoid, and how to prep vegetables for a happy gut.

Vegetables are packed with nutrition, but they can be hard to incorporate into your diet when you have ulcerative colitis — especially during a flare. Still, that doesn’t mean you need to avoid them completely.

Vegetables not only provide essential nutrients but can also contain prebiotics, a type of fiber that helps boost the growth of healthy gut bacteria, explains Ryan Warren, RDN, who specializes in nutrition and counseling for patients with gastrointestinal (GI) conditions at the Jill Roberts Center for Inflammatory Bowel Disease at Weill Cornell Medicine in New York.

Research backs this up: People with ulcerative colitis who followed a high-fiber, low-fat diet for four weeks experienced lower levels of unhealthy gut bacteria and inflammation and reported a higher quality of life than those who followed a typical American diet, according to a small study published in June 2021 in the journal Clinical Gastroenterology and Hepatology.

That said, not all veggies are created equal, and you may tolerate certain cooking methods more than others, particularly when you’re experiencing symptoms.

What Are the Best Vegetables for Ulcerative Colitis?

While every gut is different, many people with ulcerative colitis find that they can tolerate a wide range of vegetables when their symptoms are in remission (or they haven’t recently had GI surgery), says Arielle Leben, RD, a member of the Inflammatory Bowel Disease Center Clinical Care Team at NYU Langone Health in New York. These may include:

• Peeled, shredded carrots
• Peeled butternut squash
• Peeled acorn squash
• Peeled zucchini
• Peeled summer squash
• Peeled potatoes
• Peeled sweet potatoes
• Green beans
• Asparagus tips

What makes these vegetables a particularly good bet? Many are high in soluble fiber, which pulls water into the GI tract to turn the fiber into a thick, gel-like substance during digestion. “This type of fiber may be beneficial to patients in a flare experiencing diarrhea, because it slows digestion and can improve the consistency of bowel movements,” Leben says.

At the same time, they’re lower in insoluble fiber, which can be irritating to the gut, particularly during a flare. “When experiencing active symptoms, a diet low in insoluble fiber can be part of the management process to reduce … irritation in the GI tract,” Warren explains. Avoiding insoluble fiber might help prevent or reduce bloating, diarrhea, or abdominal pain.

Not all of these vegetables may be right for everyone, and you might find that you can tolerate certain vegetables when you’re symptom free but not during a flare. Ulcerative colitis diets aren’t one size fits all, varying from person to person, Warren says.

How to Prep Vegetables for Ulcerative Colitis

Cooked vegetables are often easier to tolerate than their raw counterparts, especially when you’re in the middle of a flare. Altering the texture can be helpful, too. You can make veggies easier on your GI tract by:

• Peeling them Peeling vegetables such as carrots, parsnips, turnips, squash, and potatoes strips away some of the insoluble fiber, making them less irritating to the gut, say Warren and Leben.
• Cooking them until soft Methods that make veggies tender without the need for too much added fat tend to be best. (Greasy foods can often trigger symptoms, notes Cleveland Clinic.) Try baking, roasting, steaming, or lightly sautéing, Leben recommends.
• Mashing or pureeing them, if needed Particularly during a flare, purees and very soft textures can be easier to digest. “Texture changes can help break down fibrous foods and improve tolerance,” says Leben. Try mashing soft-cooked veggies or blending them into soups or smoothies, Warren recommends.

Vegetables to Avoid with Ulcerative Colitis

When it comes to veggies that can potentially trigger your symptoms or make them worse, cruciferous vegetables, such as broccoli, cauliflower, Brussels sprouts, and cabbage, are often at the top of the list. “They’re common triggers for gas and bloating, regardless of whether they are raw or cooked,” Leben says. Depending on how they affect you, you may find that you need to steer clear during flares or cut them out of your diet completely. 

Be careful with large amounts of tough, uncooked greens, too, such as kale salads. While leafy greens that have been cooked until soft (and possibly blended or pureed) may be tolerable for some, the rough texture of the raw greens can be irritating, Warren notes. “But again, this will all depend on the patient,” she says.

Salads don’t have to be entirely off limits, Warren and Leben say. If you find that raw vegetables work for you when you’re not experiencing symptoms, go ahead and enjoy them in quantities you can tolerate.

Vegetables for Ulcerative Colitis: the Bottom Line

Vegetables are worth eating if you have ulcerative colitis, but it’s important to find options that work with your GI tract and don’t trigger symptoms. Soft-textured vegetables that are higher in soluble fiber and lower in insoluble fiber are often more easily tolerated, especially during a flare-up.

If you’re having trouble finding vegetables that work for you, talk with a registered dietitian specializing in ulcerative colitis or inflammatory bowel disease. “They can help determine how much fiber and what choices are best for each patient,” Leben says.