Can I eat lentils with ulcerative colitis?
By Jude Horak, UC patient. Sources checked 2026-08-12.
Also searched as: dal, red lentils, green lentils.
Have Crohn's instead? Jump to the Crohn's notes
Like other legumes, lentils contain fermentable GOS carbohydrates that can trigger gas and bloating in sensitive guts; Monash FODMAP testing shows tolerance is dose-dependent, with small servings (roughly 1 ounce boiled, more for canned/drained) being lower in FODMAPs than large portions. UK patient guidance lists lentils as a healthy protein alternative to red or processed meat and part of a fiber-containing balanced diet.
During a flare
Well-cooked, small portions of lentils (for example in a soup, blended or otherwise) are more likely to be tolerated than large servings during a flare; some people still find them gas-producing and prefer to hold off until symptoms settle.
In remission
Reintroduce gradually and pay attention to serving size, since tolerance for lentils and other legumes varies a lot from person to person even outside a flare.
What the research says about lentils and UC
Monash University FODMAP has tested lentils directly and reports that tolerance is a matter of dose. A small serving of boiled lentils, around one ounce or a quarter cup, sits within the low FODMAP range, while a larger serving crosses into high because of galacto-oligosaccharides (GOS). Canned lentils, drained and rinsed, test lower still, since the GOS leaches into the canning liquid, and Monash gives canned lentils a more generous low FODMAP portion than boiled. Crohn's & Colitis UK does not go into FODMAP detail but includes lentils among the beans and pulses it recommends as healthy protein alternatives to red or processed meat in a balanced diet.
Two honest limits apply to that evidence. Monash's data come from irritable bowel syndrome, not ulcerative colitis, and the relevance to UC is by extension: many people with IBD have IBS-like gas and bloating that FODMAP portions can help manage, but the research does not show lentils affecting inflammation either way. Crohn's & Colitis UK's endorsement is general dietary advice rather than a lentil-specific finding. Red lentils deserve a separate note. They are split and hulled, so they cook down to a soft puree with less skin than green or brown lentils, and that reduces the insoluble fiber, though not the GOS content. For a flare, that softer texture is the practical advantage; for gas, portion size remains the lever.
If you have Crohn's instead of UC
I have UC, not Crohn's, so this part is research rather than experience.
With a Crohn's stricture, the kind of lentil matters more than it does for UC. Whole green and brown lentils keep their seed coats, and Cleveland Clinic's low-fiber guide lists lentils among the foods to avoid when food needs to pass a narrowing in small particles. Split red lentils have had that outer coat removed and collapse into a smooth puree when simmered long enough, which fits the AGA's 2024 practice update: people with symptomatic strictures may tolerate plant foods better when they are cooked or processed to a soft consistency.
A red lentil soup blended smooth is therefore a very different test from a salad of firm green lentils. Without a stricture, the portion and gas advice elsewhere on this page applies much as it does in UC.
Based on: Cleveland Clinic; American Gastroenterological Association (AGA); National Institutes of Health (PMC), from Frontiers in Nutrition 2023. More on how Crohn's and UC diets differ.
Ways to make it gentler
- Cook until very soft and start with small portions (about 1 ounce boiled)
- Rinse canned lentils well before eating
- Try red lentils, which break down softer than other varieties
Safer swaps
- tofu
- eggs
- lean meat or fish
How I handle lentils
Red lentils are my compromise legume. They cook in fifteen minutes into something close to a puree, they have almost no skin, and a small amount stirred into a soup gives me protein and body without a mouthful of individual lentils to work through. During a flare I either skip lentils or keep them to a couple of spoonfuls of well-cooked red lentil dal thinned with broth, and I pay attention to how that goes before having more. In remission I make a bigger pot of dal with turmeric, ginger, and a little cumin, leaving out the onion and garlic and using garlic-infused oil instead. Green and brown lentils I eat less often, mostly in salads when I am feeling solid, because their skins are noticeable to me. Canned lentils rinsed well are my shortcut for a quick lunch bowl.
How much, and how to test it
Start with about a quarter cup of well-cooked red lentils, or the same amount of canned lentils rinsed thoroughly, folded into a soup or rice dish you already tolerate. Skip onion and garlic in the pot for the first attempt so they do not confuse the result. Over the next one to two days note gas, bloating, cramping, and any change in stool frequency. If that goes cleanly, add another quarter cup on a later day, then try green or brown lentils. Returning bloating at the same portion is the cue to stay at the lower amount or take a break.
What you get from lentils
Half a cup of cooked lentils provides about nine grams of protein, roughly eight grams of fiber, and strong contributions of folate, iron, potassium, and manganese. The iron is non-heme, absorbed better alongside vitamin C, and useful when colitis-related blood loss has lowered iron stores. Potassium helps replace what diarrhea removes. Red lentils, once hulled and cooked soft, deliver this with less insoluble fiber than whole green lentils, which is why they suit a sensitive gut better.
Why this one shows up on trigger lists
Lentils is flagged for 2 of the properties that most commonly cause UC symptoms. Each page explains the mechanism and lists every other food that carries it.
Questions people ask about lentils and UC
Can I eat lentils with ulcerative colitis?
In remission, many people can, and UK guidance lists lentils among the pulses it encourages as an alternative to red meat. The typical problem is gas and bloating from fermentable GOS sugars rather than inflammation, and it scales with portion. Small servings of well-cooked or canned lentils are where most people start. During a flare, some tolerate a little red lentil soup while others prefer to wait.
Are red lentils easier to digest than green lentils?
For texture, yes. Red lentils are split and hulled, so they cook to a soft mash with little skin, which means less insoluble fiber to move through an irritated colon. Their GOS content is similar to other lentils, so the gas potential per portion is about the same. Choose red for softness during a sensitive stretch and manage gas through portion size.
Is dal okay during a colitis flare?
A thin, well-cooked red lentil dal in a small portion is one of the gentler ways to try lentils during a flare, and some people manage it well. The risks are the portion, which should stay small, and the seasoning, since onion, garlic, and hot chili are common additions that each carry their own trigger potential. A plain dal with turmeric and a little salt is the version to test first.
Why do lentils give me gas but not diarrhea?
Gas comes from colonic bacteria fermenting the GOS in lentils, which happens in nearly everyone to some degree and is not a sign of damage. Diarrhea from lentils is less common and more often relates to larger portions, the fiber load, or other ingredients in the dish. Monash FODMAP testing suggests that keeping to small canned or boiled portions reduces the fermentable load and, with it, the gas.
Do lentils need to be cut out completely with a Crohn's stricture?
Not necessarily, and the evidence is thinner than many people expect. A 2023 systematic review of nutrition in stricturing Crohn's found only five eligible studies and none that tested fiber modification or low-residue diets as a stricture treatment. Current expert advice is to keep insoluble fiber low, and the review suggests a pattern richer in soluble fiber and resistant starch as an option that still needs study. Soft, pureed red lentils may suit that approach, but how much your narrowing handles is a question for a dietitian.
Sources
- Including legumes on a low FODMAP diet (Monash University FODMAP)
- Food and Crohn's or Colitis (Crohn's & Colitis UK)
- How To Follow a Low-Fiber Diet (Cleveland Clinic)
- Diet and nutritional therapies in patients with IBD (American Gastroenterological Association (AGA))
- Nutritional interventions in adult fibrostenotic Crohn's disease: A systematic review (National Institutes of Health (PMC), from Frontiers in Nutrition 2023)
Written by Jude Horak, a UC patient. Sources last checked 2026-08-12. Spotted an error? Tell me.
