Is gender reassignment surgery halal if the person is a trans naturally and not cosmetically, and if not, what does Islam instruct trans Muslims to do to help in their lives, and are there any special exceptions for them such as in attire and marriage etc?
The Qatari Fatwa Authority permits gender reassignment surgery on the condition that the person has a medical condition where their apparent sex is different from their “real” (internal / genetic) sex. For example a person with androgen insensitivity syndrome can be genetically male without developing male genitalia.
As for gender reassignment for those who feel psychologically to belong to the opposite gender, this is generally forbidden. But opinions on this issue are still in the development stage and may change in the future. Giving a genetically-male person female hormones (as it is done with those who change their sex) may have extremely negative long-term consequences for the person’s health, and since the rise in gender reassignment is recent, there are not many long-term studies on its effects.
References
- Fatwa from the Qatari Fatwa Authority (Arabic PDF)