Eating a high-fiber diet is thought to help prevent development of pouches (diverticula) in the colon.
Doctors recommend that you eat 25g to 35g of fiber every day. Packaged foods and fiber supplements include the amount of fiber content in the nutritional information. You should increase the amount of fiber in your diet slowly so that your stomach can adjust to the change. Adding too much fiber too quickly may cause stomach upset and gas. To get adequate fiber in your diet:
Some doctors recommend adding bran to your diet to help boost the fiber content. If you do this, start slowly with 1 teaspoon a day. Gradually increase the amount to several teaspoons a day.
Some people avoid nuts, seeds, berries, and popcorn (because of the hulls), believing that the seeds and nuts may get trapped in the diverticula and cause pain. But there is no evidence that seeds, nuts, and berries cause diverticulitis or make it worse.1
Drink lots of fluids every day to help keep your stool soft. High-fiber diets need lots of fluid in the body to work properly.
If your diet is high enough in fiber, your stools should become softer, larger, and easier to pass.
When trying to change what you eat, it is easy to get off track without realizing it. It may help to keep a food diary.
Citations
WebMD Medical Reference from Healthwise