Hello, Helpful Bees! ๐Ÿ

I need some advice for working through a potty training regression with my son ๐Ÿ‘ฑโ€โ™‚๏ธ. Some background:
โ€ข He is a "young" four. In that, I mean, he was born NYE 2014 and is very hyper, playful, and curious. ๐Ÿ˜‚ He is a class clown and loves attention.
โ€ข G has been potty trained 9x since he was 2. (YES, YOU READ THAT CORRECTLY! ๐Ÿ™„๐Ÿ˜ถ๐Ÿ˜ถ๐Ÿ˜ถ) 95% day success using the toilet but had yet to master nights ... He regresses when we have company for an extended stay, we visit family (in another state) for more than a couple days, OR when he attends day camp.
โ€ข G's latest regression has been after my parents came for a visit for a week (before my surgery) and we were taking day trips in which toilets were not always readily available/accessible on-demand. He would wet his pants so we would change his clothes (AND I began to put a pull-up on OVER his training undies). After they left, he would still occasionally wet ... even at home. ๐Ÿคฆโ€โ™€๏ธ
โ€ข NOW, G has begun to hide to poop ๐Ÿ’ฉ [in his pants]. I believe he is doing it because he does not want to "miss out" on anything. In any case, I can not always "catch him" and place him on toilet before he goes. ๐Ÿ˜–

I am so frustrated as I have [successfully] potty trained many children but G is a tough little nut to crack!

I have tried:
- making him go on a timer
- positive reinforcement (using his Garmin Vivofit JR to track his potty use, earning special books, and Kindle time)
- bribery (sugarfree lollipops)
- making the bathroom a comfortable place (* "potty books," magnadoodle, water doodle, tiny radio, etc)

I am losing my mind ๐Ÿง  and so tired ๐Ÿ˜ด of cleaning up human waste messes from my little guy.
Please, help me, ๐Ÿ bees!
TIA!
- Kaohinani ๐Ÿ’‹