Crohn's disease and ulcerative colitis are conditions collectively known as inflammatory bowel disease (IBD). Unlike ulcerative colitis, which affects only the large intestine, Crohn's disease affects the small intestine, where most of the absorption of food takes place. Therefore, people with Crohn's disease are at high risk of malnutrition. Although Crohn's disease is not caused by the foods you eat, paying attention to what you eat is important in reducing symptoms and promoting healing.
Foods to Avoid
In an acute flare-up, bowel rest may be required. Sips of clear fluids are usually fine, and parenteral nutrition (infusing nutrient solution into vessels or central vein) may be needed to supplement minimal intake. When solid food is tolerated, a low-residue diet is recommended to reduce discomfort and pain. Foods such as nuts, seeds, corn fruit with skin and raw vegetables should be avoided. High-fat foods should be restricted, as they may cause diarrhea and gas if fat absorption is incomplete. Dairy products may need to be limited due to secondary lactose intolerance. If corticosteroids (an anti-inflammatory medication) are used, sodium intake needs to be restricted to 2 g per day to avoid fluid retention.
Soft Diet
Once solid food is tolerated during the acute phase, a soft diet with easily digestible and mildly seasoned foods is encouraged. Your doctor may recommend nutritional supplements to maximize protein, vitamin and mineral intake to promote healing. If a corticosteroid is used, an increase in potassium intake with foods such as bananas and potatoes is recommended. When in remission, patients can resume a normal diet with 25 g of fiber daily.
Nutritional Problems
Crohn's disease can strike anywhere in the entire length of the gastrointestinal (GI) tract; 80 percent of the patients have attacks in the small intestine, so nutrients cannot be properly digested and absorbed. Most patients also have severe diarrhea during flare-ups. Along with fat malabsorption is malabsorption of fat-soluble vitamins A, D, E and K. Protein loss and anemia are also common due to bloody diarrhea.
Supplements
In addition to a balanced diet, vitamin and mineral supplementation usually is recommended for people with Crohn's disease. All fat-soluble vitamins (A, D, E and K) need to be supplemented, with at least 800 IU of Vitamin D and 1,500 mg of calcium daily for bone health. For those taking the medication sulfasalazine, a folate supplement (1 mg daily) is needed. With iron deficiency, oral iron supplementation in the range of 18 to 27 mg taken one to three times a day may be needed.
Fluids
In Crohn's patients, foods are not completely digested in the small intestine, and when food travels through the colon, it interferes with water conservation causing chronic diarrhea. Dehydration is a main concern. A good rule of thumb is to drink a half-ounce per day for every pound of body weight (for example, if you weigh 150 lbs., you should consume at least 75 oz of water per day).
References
- "Gastrointestinal Disorders and Nutrition"; Tonia Reinhard, M.S., R.D.; 2002
- Crohn's and Colitis Foundation of America: Diet and nutrition
