But I'll be honest. When I read the statistics on the rise in anal sex, I was taken aback. Women are suddenly having gobs of it: 40 percent of us, ages 20 to 24, have tried anal sex, up from 16 percent in 1992, found a survey published in The Journal of Sexual Medicine in 2010. The number of women ages 20 to 39 who say they've done anal in the past year doubled to 20 percent. And 20 percent of women in relationships have had anal sex in the last three months.