Dawn Lambert was just 20 years old, with one year's service in the Navy, when she agreed to undergo exploratory surgery in January 1982 for what doctors believed to be a problem with her fallopian tubes.

Almost four years later, the slender blond says she is a changed woman -- older, wiser and unable to have a child because doctors at the Naval Hospital at Portsmouth left five sponges and a plastic marking device in her body and allowed them to fester unchecked for months.

"There was no excuse for it," said Lambert as her testimony before a House panel yesterday turned into sobs. "I was only 20 years old. I could have had children . . . I don't see how they can do these things and then say they have no moral responsibility."

Lambert, a former seaman recruit in the Navy, was one of seven persons who testified yesterday before a House Judiciary subcommittee considering a bill to give active duty members of the armed services the right to sue the government for improper medical care received in military hospitals. A 1950 Supreme Court ruling containing what became known as the Feres Doctrine bars service members from suing for an injury suffered during active duty.

The bill, sponsored by Rep. Barney Frank (D-Mass.), is to be the focus of a second hearing at 2 p.m. today. Representatives of the Justice Department, the Defense Department and the Veterans' Administration are scheduled to speak.

The Feres Doctrine and military medical care have come under tough scrutiny in the last few months after an unprecedented series of audits showed some Army, Navy and Air Force hospitals did not follow many health care standards established by the Defense Department. Reforms have begun at individual hospitals and throughout the services, departmental spokesman have said.

Frank yesterday called his bill an attempt to enforce accountability at military hospitals. Frank repeatedly asked witnesses whether they had received compensation for their injuries or if doctors involved with their cases has been investigated.

Lambert said she receives a $66 monthly disability check, because she was medically discharged by the Navy in June 1982. The Navy has promised to reimburse her for the civilian care she has since received, Lambert said, but she hasn't yet seen a check for the nearly $12,000 she owes.

Never, she added, has she been told that the doctor who operated on her was disciplined. "I'm in debt . . . and we were told that nothing probably happened to the doctor because it was his first incident," Lambert said.

Lambert was not alone in her anger. For three hours, military personnel and their families offered other testimony in support of a change in the law.

Petty Officer 1st Class Doyle Stanley, whose history of poor medical care from the Navy was chronicled by The Washington Post in February, told how he lost a major part of his skull to a staph infection that was ignored by Navy doctors.

"Why did you go to a civilian doctor when you had the opportunity to get free medical care from the military?" Rep. Dan Glickman (D-Kan.) asked Stanley. "Because the free medical care wasn't doing me very much good, sir," Stanley said.

Doreen Forsman, wife of Air Force Maj. Gen. Billy B. Forsman, told how her husband, the former director of intelligence in Europe, died of kidney cancer in November 1981. He died, she said, because the cancer for too long went undetected by doctors at the Air Force Hospital in Weisbaden. She also alleged officials engaged in a coverup.

"Besides the pain of cancer," Forsman said, "my husband had to face the pain of knowing that after 30 years of service, the Air Force had betrayed him."

Forsman was one of three speakers representing Citizens Against Military Injustice, a three-year-old organization that has been lobbying for changes in the Feres Doctrine. Frank Savala, CAMI president, said after yesterday's hearing that his group was "just trying to get the military to be held responsible for its actions . . . to let servicemen have the same kind of justice that everybody else has."