December 24, 2007
Using Low-Fiber Diets For Crohn's Disease Sufferers
Dietitians and physicians usually recommend increasing fiber in your diet for overall good health. Fiber is important for weight management. Fiber may help manage blood sugar in diabetes; it may help manage diverticulosis; it may help reduce cholesterol; and it may help protect against some kinds of cancers. While eating fiber, you feel full sooner and may eat less. Despite these clear health benefits, your doctor or dietitian may ask you to limit fiber in your diet because you have IBD. The priority when you have an IBD flare is to recover, return to better health, and have improved quality of life. This may require adjusting or reducing your fiber intake.
Low-Residue Diet
In clinical practice, a low-residue diet limits foods that increase the amount of undigested food matter and the amount of stool produced. Low-residue diets allow soluble fiber, but limit insoluble fibers and foods that could potentially contribute to food-related obstructions.
This fiber-restricted diet is intended only to be a short-term diet to help you feel more comfortable by decreasing gastrointestinal intolerance symptoms from a flare or from a change in the normal anatomy after surgery. This not a fiber-free diet; rather, there is a compromise by allowing soluble fiber until you can comfortably include sources of insoluble fibre in your diet again. The goal is for you to return to a regular diet once your disease and symptoms have improved. In the meantime, be sure to plan meals in advance so that you can find acceptable alternatives and have them available to you when you are hungry.
TIP: Fiber is the structural part of plants (vegetables, fruits, grains, and legumes). Human digestive enzymes cannot break down fiber; however, some bacteria in the gastrointestinal tract can break it down. Dietary fiber can be fermented by colonic bacteria to produce short-chain fatty acids (SCFA), which are absorbed and provide the body with energy (used specifically by the cells that line the intestine and your liver). Fiber is commonly classified according to its solubility (ability to dissolve in fluid) as insoluble or soluble. Insoluble fiber is not easily fermented by bacteria and is best known for bulking stool and relieving constipation. It increases the fecal weight and speeds up the passage of material through the intestines. Soluble fiber is fermented by many bacteria in the large intestine and is best known for its favorable effects on cholesterol. It also slows stomach emptying and passage of material through the intestines, helping to form or gel loose bowel movements. Both kinds of fiber slow starch breakdown, thus slowing glucose absorption into the bloodstream; both create a full feeling; and both contribute to gas production (and thus need to be introduced and increased gradually in the diet), although some soluble fiber will tend to produce more gas.
Long-Term Low-Fiber Diet
There are times when a low-fiber diet needs to be followed over longer period of time. Such is the case when you have narrowing of the bowel due to scar tissue or stricturing of the intestine in Crohn's disease. When there is narrowing, the bowels must push hard to pass undigested food matter through the narrowed area. This causes cramping, pain, and, in some cases, abdominal bloating and nausea.
Similar situations of bowel narrowing occur with inflammation from active Crohn's disease and bowel-wall swelling following surgery. This is usually temporary because the swelling decreases with treatment or time and the size of the opening of the bowel returns to normal. Unfortunately, scar tissue remains despite treatment with medication. In that case, the narrowing is permanent, unless it is surgically removed or corrected.
Long-term compliance with a low-residue diet brings unique challenges for ensuring that vitamins, minerals, and trace elements are adequate considering the many restrictions to the fruits and vegetables food group. The key is to rely on fruits and vegetables that are canned, well cooked, squeezed into juices, or blenderized and strained. Sometimes a multivitamin and mineral supplement is needed.