When is it ok to masturbate for a male patient who has undergone a full tummy tuck with muscle repair?

Questions about sexual activity after surgery are very common, but can be somewhat embarrassing to address with your surgeon, so I applaud your courage for asking this question in an online forum.  I would be less worried about masturbation causing muscle damage or stretching than I would actual physical sexual activity with another person.  Unless your orgasm is particularly rigorous, you should be fine with masturbation within a few days or at most a couple weeks.  Sexual activity I would suggest you clear with your surgeon.  Best of luck with your recovery!