This is sometimes called 'linguistic feminism,' and the big names here are Kristeva and Cixous. This particular branch of literary theory depends heavily on gender essentialism, or the idea that there are certain characteristics which belong virtually exclusively to each gender. A lot of people object to this idea, but there is a way around it. With that in mind, let's get into the theory. The first tenet of this theory is that language does not belong to women.
Language is a male artifact, part of a male culture, and has been shaped to meet men's needs.
Men's language includes, but is not limited to, the ultimately cold and patriarchal complex of logic and reasoning which has so dominated Western discourse that for a woman to even be understood in literary theory, she has to write in that discourse community and therefore validate it. Men's language is the language of law, of authority, and it is a language that ignores emotion. Women's language, because of this, is mostly limited to nonrational utterances and evocations like laughter, screaming, grunts and moans. However, these theorists are attempting to forge a new tradition of women's writing, and so their writings can be a little hard to read, particularly if you are used to reading standard literary theory. Well, Cixous and Kristeva both talk a great deal about penises, vaginas, orgasms and a whole lot of other things you generally don't expect to see in a literary theory.