BOSTON — Area legislators, unhappy with a plan to allow transgender public-school students to choose which gender bathrooms and locker rooms to use, have met with Education Commissioner Mitchell Chester to push for a policy that defines a student’s gender on anatomy, not self-identification, when using sex-segregated facilities.

“An anatomical male in a locker room could make girls feel uncomfortable and vice versa,” said Rep. Colleen Garry, D-Dracut, prior to joining other lawmakers in their meeting with Chester on Friday.

Legislators want to change a policy set by the Department of Elementary and Secondary Education last week that expands the 2011 anti-gender identity discrimination law to allow transgender students to use their preferred bathroom or locker room.

The lawmakers are also backing a bill sponsored by Garry that would dictate a change in the rules.

Garry said the Legislature discussed the issue in 2011 as part of the debate over the anti-discrimination law, but left the facilities issue out because it could violate other students’ privacy.

“The (2011) bill was not to accommodate locker rooms and bathrooms, but the commissioner took it upon himself to provide guidance to schools,” Garry said.

Garry said Chester was not willing to revoke the department’s guidelines yet, but she stressed that the guidelines are not law.

“This is guidance; it’s not regulation,” Garry said. “It’s their interpretation of how schools should handle things.”

JC Considine, director of media relations for the education department, said the department has no plans to rescind the guidance.

Rep. Sheila Harrington, R-Groton, said the legislators discussed adding separate facilities, such as teacher bathrooms, for students who feel uncomfortable using bathrooms due to a gender issue.

“Obviously we’re very sensitive to people with transgender issues, and we’re trying to be compassionate, but we want to be respectful of the privacy of all people,” Harrington said.

Rep. Marc Lombardo, R-Billerica, along with Rep. James Miceli, D-Wilmington, and eight other representatives, backed the bill to ensure what he said was the innocence and safety of Massachusetts children.

“It’s time we say enough to this radical social agenda promoted by the administration and use common sense to protect our children,” Lombardo said.

Massachusetts is one of 16 states, along with Rhode Island and Vermont, which have transgender anti-discrimination laws. There is little data on how many transgender students are in Massachusetts.

Jesse Begenyi, executive director of the Massachusetts Transgender Political Coalition, said Garry’s bill does not protect transgender-student rights.

“They are students who aren’t trying to be disruptive,” Begenyi said. “They are trying to fit in and use the appropriate facility to fit in.”

Begenyi said Garry’s bill could cause more violence against transgender students.

“Transgender students know what’s safest for them, and to have someone telling them where they need to be — that’s unsafe,” Begenyi said.

According to a 2009 report by the Gay, Lesbian, and Straight Education Network, a nonprofit New York-based advocacy group, 89 percent of transgender students said they have been verbally harassed, and 55 percent say they have been physically harassed.

Grace Sterling Stowell, executive director of Boston Alliance of Gay, Lesbian, Bisexual, and Transgender Youth, said allowing transgender students to choose their own facility might make some students uncomfortable, but that concern should not be the state’s priority.

“There’s a difference between comfort and safety, and the people who are unsafe are the transgender students,” she said.

Brian Camenker, executive director of MassResistance, a Waltham-based pro-family group, criticized Garry’s bill for being “wishy-washy.”

“We think the bill is misguided to say the least, and a cowardly approach,” he said.

Camenker called gender identity “medical quackery,” and said the only solution is to repeal the 2011 law.

Andrew Beckwith, executive vice president of the Massachusetts Family Institute, said the bill would reinstate the 2011 discrimination law’s original purpose and close any legal loopholes.

“Anatomy is a (clear) distinction, whereas gender identification is fluid and can flow back and forth,” Beckwith said. “The law enacted a broad standard, but the commission took it to the extreme.”