Some newspapers pull 'Doonesbury'

It's OK to portray the president as a wimp, a waffle or a reckless Roman emperor.

But if you're "Doonesbury" creator Garry Trudeau and you mention the "M" word -- as in masturbation -- editors will pull your strip.

Characters in Sunday's strip discuss a recent study by Australian scientists who found that men who masturbate often in their 20s are 30 percent less likely to get prostate cancer later.

Some U.S. newspapers have chosen to run a substitute offered by Kansas City-based Universal Press Syndicate.