Allycaterpillar

Hi, I am a classical/opera singer and was asked to sing at a concert 8 days after my Gastric Bypass surgery but I am unsure if I will be able too since I used my abdominal muscles to sing and support my breadth (the Bel Canto technique for anyone who understands). I am assuming that because of the stitches it would be unwise to sing so soon after my surgery since. I was wondering if anyone here has any experience regarding this or can tell me what their post bariatric surgery instructions where regarding rest and healing. Thank you