Fiber and Lactose
Fiber and lactose are two common food substances that can cause problems with diarrhea.
Fiber comes from the portion of plants that is not digested and, therefore, passes intact through the digestive tract. There are two classes of fiber: fiber that dissolves in water (soluble) and fiber that does not (insoluble). Insoluble fiber can increase the rate of food passing through the digestive tract, whereas soluble fiber can decrease the rate.
If your intestinal tract is irritated, the normal amount of insoluble fiber may be too much. Minimizing your intake of insoluble fiber may help relieve diarrhea.
To reduce the amount of insoluble fiber in your diet, avoid the following foods:
- Wheat bran
- Whole grains
- Dried fruits
Instead of the foods above, try to eat the following:
- Tender cooked vegetables Examples include canned or cooked tender asparagus, beets, carrots, pumpkin or squash.
- Canned or cooked fruits Examples include canned applesauce, apricots, peaches and pears. Ripe bananas and citrus fruits without seed and membranes also are fine.
- Refined starches Examples include refined, cooked or dry commercially prepared corn, oat, rice or wheat cereals, enriched white, refined wheat or light rye bread, noodles from refined flour, rice without the hull and potatoes without skin.
To increase the amount of soluble fiber in your diet, try eating:
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.