Dear Dr. Donohue: Please give me some advice about diverticulitis. What shouldn't I eat? I have had so many different answers to this question that I am now very confused.

- G.C.

A: A diverticulum is a small, goblet-shaped pouch whose stem emerges from the colon. "Goblet" might give you the wrong picture, though, because a diverticulum is only one-fifth to two-fifths of an inch in diameter, the size of a small pea. "Diverticulosis" implies people have a few to hundreds of diverticula, and most often they are silent - no pain, no symptoms. Nearly 50 percent of adults have some diverticula by the time they are 60, and close to 100 percent have them by 80.

Diverticula arise because hard, dry stool requires that the colon produce great force to move undigested food through it. That force pushes the colon lining through the colon wall - creating a diverticulum. A high-fiber diet keeps stool moist and soft. That's the diet for diverticulosis. Fruits, vegetables and whole grains are sources of fiber. Whole grains are grains that haven't been refined. They still have their outer coat, the bran. At one time, it was widely held that seeds and things such as corn, nuts and popcorn were banned from a diverticulosis diet. The thought was that they could plug the stem of the diverticulum and cause it to become inflamed. This theory has been disproven.

Diverticulitis is another story. It's inflammation of diverticula, and it is very painful. Somewhere between 10 percent and 25 percent of those with diverticulosis will experience an attack of diverticulitis. With an attack of diverticulitis, people are taken off food and often have to be hospitalized and fed intravenously. Antibiotics fight the inflammation. A high-fiber diet goes a long way in keeping diverticulosis from becoming diverticulitis.

The booklet on diverticulosis and diverticulitis explains these conditions and their treatment in detail. Readers can obtain a copy by writing: Dr. Paul Donohue - No. 502, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 with the recipient's printed name and address. Please allow four weeks for delivery.

Fiber may help here, too

Dear Dr. Donohue: I am 28 and have a question about bowel movements. I have one about twice a week. I have even gone as long as a full week without having a movement. I don't go until I feel the need. Is this normal, or should I seek medical help?

As far as my eating habits, I eat three meals a day. On occasion, I forgo breakfast. I have no pain, no cramps and no indication of anything wrong.

- A.G.

A: Having a bowel movement every three days, or twice a week, isn't outside norms. Constipation is predicated more on the difficulty of eliminating stool than on the number of stools per week. So long as you're not straining to evacuate rock-hard stool, things are OK.

One full week without a movement is not normal.

How much fiber do you eat? Fiber is the indigestible part of foods. We're supposed to get 25 to 35 grams of it a day. Kellogg's All Bran and General Mills' Fiber One have 10 or more grams of fiber in a half-cup serving, an apple has 4 grams, and half a cup of peas has 5 grams. If you can't get enough through food, turn to some commercial products such as Metamucil. And if you want a cheap and easy-to-use fiber source, go to a health-food store and buy bran. You can sprinkle it on any food you want.

Germ causes stye

Dear Dr. Donohue: In the past few months, I have had several styes. What causes them? I had one as a child, and then not any for more than 60 years.

- D.B.

A: A stye is an infection of one of the eyelid glands. The infecting germ is usually the Staph germ. Warm compresses bring a stye to a head, which drains and heals. Sometimes, antibiotic ointments containing erythromycin or bacitracin are needed.

Flu protection

Dear Dr. Donohue: I just had a flu shot. How long does it take after the shot before am I protected against infection?

- D.J.

A: The shot rouses the immune system to make antibodies, the body's bullets against infecting germs. Antibody production peaks about two weeks after the shot.

Protection lasts for at least six months.

Dr. Paul Donohue writes for North America Syndicate. Send letters to Box 536475, Orlando, FL 32853-6475.