Fleg, in his fourth year of training at UNC, is national coordinator of the American Medical Student Association's effort to wean medical schools from their pervasive relationships with drug companies. And he's had quite a year.

Fleg helped AMSA's PharmFree campaign, established in 2002, produce the first scorecard to grade medical schools based on whether they have policies curbing the pharmaceutical industry's influence. The effort generated national press coverage. He also expanded PharmFree's national annual awareness day to an awareness week this fall, giving the issue its biggest splash to date.

In October, Fleg testified before the U.S. Senate, explaining why he believes physicians who accept lunches and even small gifts such as notepads and mugs from drug companies open the door to influence. In the end, he contends, the sacred doctor-patient relationship is compromised.

Fleg's zeal for the cause is boundless.

Fleg's wife, Shannon Fleg, who is expecting the couple's first child this summer, jokes that her husband will probably be at her side in the delivery room with a tiny PharmFree sign for the baby to hold.

It would be easy for such a strident advocate to become a figure of controversy and strife. But colleagues and mentors say Fleg, who stands 6-foot-4 and towers over most people, tempers his principles with a genuine respect for others' opinions, even when they are at odds with his own.

He frequently uses humor to challenge the status quo and invite conversation. Fleg signs his e-mail messages with offbeat taglines such as, "Card-carrying member (with overdue fines), Chapel Hill Public Library," or "Intramural Debate Team Alternative (occasionally), Atholton High School." It's Fleg's way of getting a smile while poking fun at the self-important practice of following one's name with credentials and associations -- common among physicians.

Fleg's main purpose at UNC this year has been to persuade the medical school to adopt a policy limiting pharmaceutical company involvement in hospital and academic programs. UNC has no formal rules limiting or banning drug company activities on campus.

PharmFree isn't Fleg's only cause.

He and his wife, Shannon, a Navajo Indian from Arizona, established the Native Health Initiative, which partners with American Indian tribes in North Carolina to improve health and well-being. Fleg, who taught third- and fourth-graders in inner-city Baltimore before enrolling in medical school, is in the Chapel Hill public schools on a regular basis as a speaker and mentor.

Fleg is determined that a career in medicine, and the financial rewards that often accompany it, won't change his principles. After completing his residency training, Fleg will practice in a federally designated health-care shortage area as a member of the National Health Service Corps.

In exchange for Fleg's commitment, the U.S. government is footing the bill for his medical education. The deal will allow Fleg to graduate from UNC debt-free. But Fleg says serving in an area where doctors are most needed won't be much of a sacrifice.

"It's something I'd be doing anyway," he says. "It's ultimately what is going to make me happiest."