The term FGM, female genital mutilation, is known widely around the world.
The practise involves the removal of young girls' clitorises and in most cases it's done brutally and unhygienically.
The ritual is mostly carried out in African communities, but the BBC has found that it occurs in the UK and the US too.
More common in the UK is labia stretching, the process which sees a woman having her labia minora (inner lips of the vagina), pulled by hand until they stretch up to five inches.
Researchers found that this often happens to young girls who haven't yet reached puberty… even though it's illegal.
But surprisingly, the research found that some adult women are opting to have the procedure done so they will be "more attractive to men."
These women believe that it will improve a man's sex life by giving them "something to touch," and therefore, make them "more faithful."
Some women believe that stretching their labia will make childbirth easier, but according to Eney Mhiza, a sexual practises researcher at Wolverhampton University, "these are just myths."
As part of the BBC's short film about labia stretching, a woman named Betty confirms the grim reality of FGM .
Betty had FGM done to her as a child when she lived in Zimbabwe, and now campaigns against it.
She explained, "Elderly women tell little girls to open their legs, the lips of your private parts… just the inside, they start pulling the little things out.
"It was so, so inhuman, so terrible," Betty added.
While Betty wants to warn young women and children off the idea, the BBC found that others are encouraging their daughters to do it.
They found a woman living in the UK, who tried to have the practise done on her 12-year-old daughter.
Her daughter refused to go through the process as it was too painful, but her mother said that the procedure is "expected" in her culture, and therefore is not a form of abuse.
The practises are carried out so secretly, that nobody has an official figure of how many women go it.
