DEAR DR. ROACH: For 58 years, I've been walking around with a visible tracheostomy scar on my throat, leading the curious to ask: "Yuck. What happened there?" My answers have changed over the years, but were usually something like: "I was 4. A doctor had to cut my throat open so I could breathe." But now, I don't wait for the question. Lately, my scar has helped me do some show-and-tell about what causes this near-fatal closing of the windpipe and why doctors don't see kids dying from Haemophilus influenzae anymore. Could you elaborate? — M.A.P.

ANSWER: Haemophilus influenzae (often called H. flu or Hib), despite its name, is not the cause of influenza (the "flu" is caused by a virus). H. flu is a species of bacteria that can cause meningitis, pneumonia and the condition you had, epiglottitis — an inflammation of the epiglottis, the structure that closes your trachea when you swallow.

Before the vaccine for Hib became available, epiglottitis was a feared and not uncommon problem. Back then, doctors were exhaustively taught how to rapidly recognize the life-threatening H. flu epiglottitis so that children could be treated quickly, which sometimes meant an emergency tracheostomy (a direct hole through the throat into the windpipe to allow breathing). That is the procedure that caused the scar on your neck. Despite treatment, 3 to 6% of cases of invasive H. flu were fatal. Your scar may be yucky, but you are lucky to have survived.

During the time I was in medical school, routine vaccination for H. flu became widespread, and the disease essentially went away. History records a 99% drop in this infection. I've only ever seen one case. Essentially the only people at risk for this disease now are those who are deliberately unvaccinated.

Your story is important: Many people feel that the diseases we vaccinate against are "no big deal," but thousands of kids per year died of conditions we thankfully almost never see today. Without continued vaccination, those days will come back.

DEAR DR. ROACH: In 2008, I had a partial sigmoid colectomy. Since then, I have had no recurrence of diverticulitis. The surgeon recommended that I not use laxatives but rather take fiber gummies to keep things moving easily in addition to drinking lots of fluids.

I am doing that, but my flatulence could power all the homes in a small city. It is difficult to control outbursts, which are noxious and embarrassing in the extreme. Is there any other way to avoid hard stools, straining and other unhealthy gastrointestinal situations? — J.S.

ANSWER: I am sorry for your embarrassment, but I agree with the surgeon that getting fiber and plenty of water is the safest and best way to prevent problems. However, maybe it isn't just the fiber, but your diet that is at least partially responsible for the increased gas. You could try reducing your intake of foods in the cabbage family, onions, beans, corn and other gas-producers. Avoid carbonated beverages and any beverage containing artificial sweeteners such as sorbitol or xylitol. In some people, changing the bacteria that live in your gut (your microbiome) through probiotic supplements and a change of diet can reduce the amount of gas produced.

There are other types of fiber supplements besides fiber gummies that might be better tolerated, or you can get fiber from food.