Insoluble fiber may make diarrhea worse. Insoluble fiber is in fruits, vegetables, whole grain breads and cereals. Oat bran is in some cereals, bread or muffins. You can also add it to other foods. Increase the fiber in your diet slowly.
Some people feel bloated and have gas if they increase how much fiber they eat too quickly.
Gas and bloating usually improve as you get used to eating more fiber. But some foods may make you feel worse. Foods that may make symptoms worse include foods high in fat or caffeine. Fat and caffeine can cause your intestines to contract, which may cause cramping. If gas is a problem for you, you might want to avoid foods that tend to make gas worse.