There is no explicit authoritative Catholic teaching on gender reassignment surgery (GRS). Catholic bioethicists have debated the origin of gender dysphoria and the effectiveness of GRS. A further ethical question is whether some forms of GRS involve “mutilation in the strict sense.” The principle of totality does not apply to GRS as the reproductive organs are a cause of distress only because the object of distress. This analysis leaves open the status of GRS which does not compromise biological function.