Herewith a short course on the constitutional law of the alimentary canal.

The question confronting customs officials when passengers disembarked at Los Angeles from Bogota, Colombia, was whether the woman was a "balloon smuggler." Such people smuggle cocaine by swallowing balloons containing the stuff, balloons that are passed through the smuggler's alimentary canal after the smuggler has passed through customs.

Two years later, the question confronting the Supreme Court was whether the Fourth Amendment's protection against "unreasonable" searches and seizures was violated by the customs officials' method of ascertaining the contents of her alimentary canal.

One inspector, who had caught many such smugglers, had reason for suspicion when he saw in her passport that she had made at least eight recent trips to Miami or Los Angeles from Bogot,a, capital of the cocaine industry. The lady spoke no English, had no family or friends here, had $5,000 in cash but no billfold, could not recall how her ticket had been purchased and said she planned to travel around Los Angeles by taxi, buying goods for her husband's store in Bogot,a.

The inspector requested a female colleague to conduct a "patdown" and strip search. It revealed that the woman's abdomen had "a firm fullness." She consented to an X-ray, but when asked, said she was pregnant. And when she learned she would be handcuffed while traveling to the hospital, she withdrew consent.

She was then given three choices. She could return to Bogot,a on the next available flight, or receive an X-ray, or remain in detention until she produced a monitored bowel movement. She chose the first, but could not get a seat on the flight leaving the next morning.

Sixteen hours after landing frm her 10-hour flight, she was showing signs of what an appeals court called "heroic efforts to resist the usual calls of nature." Then officers sought and received from a federal magistrate authorization for a rectal examination and involuntary X-ray. Before the X-ray results were in on the pregnancy test that proved she was lying, a physician removed from her rectum a balloon containing a foreign substance. She was arrested. During the next four days she passed 88 balloons containing 528 grams of cocaine.

The appeals court reversed her conviction, arguing that although customs officials had "justifiably high" suspicions, they should have quickly sought authority for an X-ray rather than waiting for natural processes to confirm their suspicions. The court said the indications of smuggling were not sufficiently clear to justify the protracted detention, which was "humiliating" to the woman.

The Supreme Court has now disagreed. It notes that the Fourth Amendment is more permissive of police power at the nation's border (where, for example, cars can be searched at random, or on the basis of the passenger's ethnicity) than in the interior of the country.

Justice William Brennan disagrees. To say that he just dissents is to match the understatement with which Japan's emperor announced surrender after two atom bombs. ("The war situation has developed not necessarily to Japan's advantage.")

Brennan has an Olympic-class capacity for alarm and for finding portents of a police state in police procedures. His dissent packs two walloping words ("disgusting" and "saddening") into its first six, and then shifts into high gear, describing what the customs officials did as "the hallmark of a police state" and "unbridled authoritarianism" in "an authoritarian twilight zone on the border."

Brennan charges that the customs officials had "at most, a reasonable suspicion." But why the "at most"? The Fourth Amendment is founded on the idea of reasonableness, no matter what the court has said. And the suspicion was not just reasonable, it was right.

The woman had a painful, humiliating experience as the customs officials did their job, which is to prevent her from practicing her chosen profession. She made a bad choice. And Justice William Rehnquist, writing for the majority, cites an early court opinion that "creative judges, engaged in post-hoc evaluations of police conduct, can almost always imagine some alternative means by which the objective of the police might have been accomplished."

The unpleasant facts of this case deserve dissemination so Americans can contemplate the nasty details of the fight to protect the nation from pandemic poisoning by drugs. Balloon smugglers are not the core of the problem. The core is the millions of stupid and criminal Americans who comprise a brackish pool of addiction and money. The law should attack demand as well as supply, and do so by making the lives of drug users as unpleasant as that woman's experience at Los Angeles airport.