Are you asking how long you should wait before having sex after having stitches? Because sure stitches dissolve fairly quickly but the tissue damage will last longer than that. Six weeks minimum is your best bet, you should have a postpartum appointment with your provider about then and you can talk to them about how your healing is going and whether your body is prepared yet at that point. I'd definitely suggest asking them about what kind of lubricant would be safe to use - I'd guess astroglide because it's water based and works safely with condoms - but you'll definitely want to use some sort of lube and be gentle with your body for a while. Nothing too rough - you don't want those tears to open back up as I'm sure you know. Good luck!
The stitches that desolve normally last two weeks.