To understand the nuances of farting, or flatulence, I called upon Dr. Michael D. Levitt, a gastroenterologist and associate chief of staff at the Minneapolis Veterans Affairs Medical Center. Levitt, 64, could well be called Dr. Fart because he is the world's leading authority on flatulence. He has had 275 articles printed on flatulence in medical journals, as either the principal author or the co-author.

In fact, Levitt's career could only happen in America. "In other countries, no way would a scientist study farts. But for reasons I can't completely figure out, farting is considered wrong in America and people are worried about it. Farts have been good to me. I've done very well, thank you."

Levitt works with four assistants out of a small laboratory on the third floor of the V.A. hospital, about a mile west of the Mississippi River. Every day he receives at least one long-distance phone consultation from a worried farter, almost always a man whose wife has prompted her husband to find out why he cuts the cheese so often.

Levitt's job doesn't end when he leaves the hospital at night, either. "Every cocktail party I go to, I always get at least one wife who comes up to me and complains about her husband's farts."