Not quite unlimited, but a pending proposal would make it a lot easier on the pocketbook. Medicare already pays for periodic colonoscopies and other screening procedures to hunt for signs of deadly colon cancer in persons over 50 or at significant risk. Now a Senate bill headed for likely passage would require all private health plans to do the same. Sen. Susan Collins supported and voted for the bill in committee. It gets strong backing from most gastroenterologists and the American Cancer Society.

The cost has kept many Americans from getting a colonoscopy. That and the minor unpleasantness at having a flexible tube probing and photographing the large intestine from anus to appendix. (In the old days, with earlier equipment and before the use of anesthetic or sedation, it could be agonizing.) Consider the fact that Medicare paid for only two colonoscopies in the year 2000, before Congress said it had to, but 46,599 of them in the six months after the July 1, 2001, mandate.

Even with insurance, somebody pays, either in taxes or in increased premiums. A Bangor internist estimates the total cost at $3,000, including the fees for the doctor, the anesthetist, the hospital and, if polyps are found, the lab. Internists sometimes joke about colonoscopies, seeing them as an easy fee for a specialist’s half-hour job with little risk. They tell of an Atlanta gastroenterologist who said, “When I guide in that endoscope, I imagine a pot of gold at the other end.” They tell a riddle: “Q. What are the indications for a colonoscopy? A. Have colon.”

But an area specialist, who has performed 5,000 colonoscopies without a single perforation of a colon and strongly supports the legislation, says the doctor now gets only about $200.

So is it a good bill or not? Sen. Collins says there were 135,000 new cases of colon and rectal cancer diagnosed and 56,000 deaths in 2001. These cancers are preventable and up to 90 percent curable if detected early. Today, she says, only 37 percent of all colorectal cancers come to the doctor at an early stage.

True enough. And the U.S. Preventive Services Task Force recommended this week that all adults age 50 and older be screened for colorectal cancer, using strategies that can include colonoscopy. It said this screening was likely to be cost-effective (costing less than $30,000 per additional year of life gained) regardless of which screening method is used.

So the bill probably should pass and the big added cost should be accepted. Yet, there is something wrong with Congress having to pass laws to make insurance companies do what they ought to be doing anyhow. And there is something wrong with having to patch up health care instead of devising a universal system to care for everyone like almost every other advanced country in the world.