Experiment with fiber.
When you have IBS, fiber can be a mixed blessing. Although it helps reduce constipation, it can also make diarrhea, gas and cramping worse. The best approach is to gradually increase the amount of fiber in your diet over a period of weeks. If your signs and symptoms are the same or worse, tell your doctor. You may also want to talk to a dietitian. If you take a fiber supplement, such as psyllium powder, Metamucil or Citrucel, be sure to introduce it gradually and drink plenty of water every day to minimize gas, bloating and constipation. If you find that taking fiber helps your IBS, use it on a regular basis for best results.

Avoid problem foods.
If certain foods make your symptoms worse, don't eat them. Common culprits include alcohol, chocolate, caffeinated beverages such as coffee and sodas, medications that contain caffeine, dairy products and sugar-free sweeteners such as sorbitol or mannitol. For some people, fats such as butter and margarine or foods high in fat such as mayonnaise, nuts, cream, ice cream and red meat also may aggravate symptoms. Be careful that your diet doesn't become too restricted, though. If you need help, talk to a dietitian. Large meals also may make your symptoms worse.

Eat at regular times.
Don't skip meals, and try to eat about the same time each day to help regulate bowel function. If you have diarrhea, you may find that eating small, frequent meals makes you feel better. But if you're constipated, eating larger amounts of high-fiber foods may help move food through your intestines.

Take care with dairy products.
If you're lactose intolerant, try substituting yogurt for milk. Or use an enzyme product such as Lactaid to help break down lactose. Consuming small amounts of milk products or combining them with other foods to slow digestion also may help. In some cases, though, you may need to eliminate dairy foods completely. If so, be sure to get enough protein, calcium and B vitamins from other sources.

Drink plenty of liquids.
Try to drink plenty of fluids every day. Water is best. Alcohol and beverages that contain caffeine stimulate your intestines and can make diarrhea worse, and carbonated drinks can produce gas.

Exercise regularly.
Exercise helps relieve depression and stress, stimulates normal contractions of your intestines and can help you feel better about yourself. Aim for 30 minutes of exercise most days. If you've been inactive, start slowly and gradually increase the amount of time you exercise.

Use antidiarrheal medications and laxatives with caution.
If you try over-the-counter antidiarrheal medications, such as Imodium or Kaopectate, use the lowest dose that helps. In the long run, these medications can cause problems if you don't use them appropriately. The same is true of laxatives. If you have any questions about them, check with your doctor.