A - What a tough situation. The person whom you are writing about certainly has a heavy burden to carry. I will certainly pray for them and ask our readers to do so as well.
I must first say that the person you are writing about has something in common with everyone else ever created - they are made in the image and likeness of God and loved infinitely by our heavenly Father. When God looks upon us as his children, he always does so with love and
compassion only wanting what is best for us, even when we are challenged at times up to our limitations and even in our imperfections and sin. Still, there is a law we must follow.
While the impulses the person might have are hard to live with - the desire to become someone of the opposite sex - they, as all of us, are called to live a life in conformity with the natural law. Thus, they cannot do anything which would take away their bodily integrity (wholeness & health). As Vatican II states:
"Man, though made of body and soul, is a unity. Through his very bodily condition he sums up in himself the elements of the material world. Through him they are thus brought to their highest perfection and can raise their voice in praise freely given to the Creator. For this reason man may not despise his bodily life. Rather he is obliged to regard his body as good and to hold it in honor since God has created it and will raise it up on the last day."- GS, 14Then the Catechism says this about the body:
"The unity of soul and body is so profound that one has to consider the soul to be the "form" of the body: i.e., it is because of its spiritual soul that the body made of matter becomes a living, human body; spirit and matter, in man, are not two natures united, but rather their union forms a single nature." - CCC, 365In other words, we are not just spirits and minds "trapped" in bodies, but are humans that are both body and spirit, united into one human being. Thus, to be human is to be both physical and spiritual. In fact, we can say that because the soul is the form of the body, we have either a male or female soul - which is defined by our bodies. Thus, to be transgendered, is not a physical or spiritual problem, it is a mental one.
These kinds of surgeries are not allowed by the natural law, thus the Catechism states:
"Except when performed for strictly therapeutic medical reason, directly intended amputations, mutilations, and sterilizations performed on innocent persons are against the moral law." - CCC, 2297I should point out that these kind of surgeries never are able to fully change the sexuality of another person - even physically. A transgendered man who has this kind of surgery will never ovulate or bear children naturally nor will a transgendered woman ever be fertile with sperm. There are also problems with the vast amounts of hormones required, which have been known to cause a number of problems, including cancer and early deaths.
Note that the Church does not allow someone who has undergone sex-change surgery to enter into marriage or become a priest or religious.
All persons who are carrying such burdens should be treated with love and compassion, because the weight of such a cross is difficult beyond measure.
I would recommend that you tell this person to contact someone at The Institute for Psychological Sciences to see if they know a professional who can help. I would also recommend they seek out another priest who knows the Church's teachings in this area, because the priest this person talked to does not.
We are all created good and our sexuality is willed to be male or female (as our bodies tell us) by God:
"Man and woman have been created, which is to say, willed by God: on the one hand, in perfect equality as human persons; on the other, in their respective beings as man and woman. "Being man" or "being woman" is a reality which is good and willed by God: man and woman possess an inalienable dignity which comes to them immediately from God their Creator." - CCC, 369