The first time I heard the word “chhaupadi,” I was standing on a rooftop in Surkhet, Nepal, in November 2017, surrounded by teenage girls. They were students at the Kopila Valley School, where my husband, Brian Lindstrom, and I had spent the previous week leading workshops in writing and filmmaking, which led to our video Op-Ed above.

Some of the girls had asked to meet with us after school to talk about their lives; we’d barely finished with introductions when one tearfully told us that she’d been banished from her home and made to sleep in a cow shed when she began menstruating. This is the way it was for many girls and women in Nepal, we learned, as the other girls told us their stories.

Not all were made to practice the chhaupadi in the strictest form. Some were allowed to stay in their homes but were confined to one room with darkened windows; others were forced to spend their days in nearby forests, permitted to return home only after darkness and required to depart before dawn.

Most were prevented from attending school while menstruating and all had severe restrictions on what they could eat, and whom they could touch and even gaze upon. Regardless of the degree and severity of the rules they were compelled to follow, what they all had in common was that each was stigmatized and isolated for a natural process.

The impact of such discrimination is profound. It’s also dangerous. Several women each year are sexually assaulted while in chhaupadi and some die — from cold exposure, snake bite or suffocation caused by smoke inhalation. In January, 35-year-old Amba Bohara and her two young sons suffocated to death when Ms. Bohara lit a fire inside her tiny menstrual hut to keep them warm. In February, 21-year-old Parbati Bogati died in an abandoned house, also of suffocation.

In an effort to end the practice, Nepal’s Supreme Court outlawed chhaupadi in 2005, and in 2017 a law was enacted that made it a crime to force girls and women out of their homes during menstruation. But the practice persists, especially in the remote regions of midwestern and western Nepal, because of deeply held superstitions about menstruation and the immense social pressure to enforce the menstrual taboo. Less severe forms of the practice — those that isolate girls and women inside of their homes rather than banish them entirely — are also common and still negatively affect women and girls.

“If we don’t, God will be angry” was a phrase Brian and I heard over and over again in our conversations with the girls, when they explained to us why their families and communities believed they must follow such oppressive rules. And this is the reason ending the practice has been so difficult.

Because the menstrual taboo in Nepal is rooted in long-held beliefs about the intrinsic inferiority of girls and women, the solution isn’t to destroy menstrual huts but to eradicate deeply internalized ideas about the female body as impure. The laws have changed, but mind-sets must change too.

The girls Brian and I met in Surkhet are doing that. With their words and their lives, they’re redefining what it means to be female in Nepal. Our most important task is to listen.