Hi
I wouldn't fix it if I were you. Read about complications after operation like that. In addition you are only 5 months postpartum!!! You will keep getting better for up to two years after giving birth so this is still too early to see how bad your rectocele is going to be.
I had a cystocele after first birth. I did hab-it (check website - there is sooooo many great info there plus exercises) two years after there was no sign of it. After this birth I had a low cervix (4cm above opening of the vagina). I'm currently 5 months pp and cervix already lifted to 6cm. I do exercises regularly but they have to be pelvic floor safe.
You should go and see a woman physio. She will point you in the right direction.
I have an appointment with urologist in July to talk about fixing my perineum. My physio thinks that if I keep doing exercises I should not need it as I will get stronger and stronger. I will see what the urologist recommends.
How bad is your rectocele? Do you feel the bulge when you stand and put the finger in? What stage is it? I'm quite shocked that your doctor said to fix it if you are only 5 months pp.....
You can also read whole woman website. They have lots of good info there about prolapse but I totally disagree with their posture. It made my back hurt a lot.
To avoid surgery and help support your rectocele you could also have pessary fitted. That would be done by woman's physio too. I'm in Australia and you can check places like the pelvic expert for more info. She believes that pessary pp will help to recover completely from prolapse. Also you can check a blog of my friend who has a rectocele and cystocele after birth. She is a trainer for women like us. Her rectocele is now gone and cystocele went from stage 2 to 1 after intensive training. Her website is Mums going strong fitness. You can find her on FB as well.
Let me know if you need more info. I'm happy to help as I have been there and kind of still am.... Let me know if you would prefer to go off forum and speak through pm.