People with Crohn’s disease may find fiber-rich foods difficult to tolerate, but that does not mean everyone needs to follow a low-fiber diet. Some research suggests fiber may support gut health and could be linked to fewer future flares, although individual responses vary.
Fiber is a plant-based carbohydrate that the body does not fully digest or absorb. Insoluble fiber adds bulk to stool and is found in foods such as fruit skins, leafy greens, nuts, seeds and legumes. Soluble fiber forms a gel in the gut and can make stools easier to pass; sources include oats, beans, barley, carrots and pear flesh.
During a flare, the amount of fiber should be guided by symptoms and tolerance. A low-fiber approach has traditionally been recommended to give the digestive tract a rest, but registered dietitian Dahlia Marin says there is limited evidence for eliminating all fiber during a flare in people without strictures. She recommends adapting food choices instead, such as peeling, cooking, blending or puréeing fruit and vegetables.
Some people may need to temporarily limit foods high in insoluble fiber, including skins, fibrous greens, nuts, seeds, popcorn and corn on the cob. For people with strictures, softer foods, thorough chewing and individualized guidance from a healthcare provider are especially important because of the risk of obstruction.
Dietitian Kelly L. Burgess says a short-term low-FODMAP diet may be considered during an active flare for people whose symptoms are triggered by fermentable carbohydrates. These include some beans and legumes, as well as cabbage, cauliflower, garlic and onions. The approach may help people with Crohn’s who also have IBS-like symptoms.
When increasing fiber, dietitians recommend starting with small portions and adding more gradually as tolerated. Soft foods such as potatoes, white rice and bananas may be easier to begin with before trying foods such as seeds, corn, celery and dried fruit. Drinking more fluids as fiber intake rises can also help soften stools and prevent constipation.
Food is generally the preferred starting point for fiber because plant foods also provide vitamins, minerals and antioxidants. Supplements may be useful in some situations, such as when traveling, but different types can affect people differently. Psyllium is a soluble, gel-forming fiber, while inulin and fructooligosaccharides are more fermentable and may cause gas or bloating for some.
Anyone struggling to eat enough, losing weight unintentionally, cutting out more foods or unsure how to add fiber after a flare may benefit from seeing a registered dietitian who specializes in inflammatory bowel disease. A gastroenterologist should be involved for new or worsening symptoms, including persistent abdominal pain, frequent diarrhea, blood in the stool, unexplained weight loss, worsening fatigue or vomiting. Severe abdominal pain, repeated vomiting, abdominal swelling, or being unable to pass stool or gas requires urgent medical attention, as these can signal an intestinal obstruction.
Sources: GQ.