Would you use a travel potty in the middle of a playground?

My 3 year old has been 100% potty trained for almost a year. Recently he's been going through a regression after a stomach bug. He's actively refusing to poop and mostly refusing to pee unless we force him to sit and distract him with a book or song.3 times this weekend he pooped in his pants while we were out of the house, twice at playgrounds a 15 minute walk from home with no bathrooms. He refuses to walk if he poops in his pants, so both instances resulted in me carrying him (poop and all), his bike and helmet home. Both times, we'd only been at the playground a few minutes before he pooped, and he did sit and "try" before we left the house.All of this preamble to say...we have a travel potty that you put bags in to contain the mess for disposal. We used it once a year ago, and he HATED it. I also feel like the idea of using a potty in the middle of a busy neighbourhood playground (no shade, shelter or privacy) was kind of weird. I've never seen anyone have their kid use one in public.It occurred to me today that in a year, he has never told us he needed to poop. Daycare take him on an hourly schedule, at home we ask him to go every few hours. If we don't prompt him he can easily go up to 8-10 hours between pees. I don't know if he doesn't know when he needs to poop, but goes when he has the opportunity, or if he does know and just actively ignores all signs until it's too late.We have never used rewards for potty training, and he is not incentivised by any food item, sticker, etc.Any advice?TL;DR 3 year old potty trained kid having poop regression...is using a travel potty in public distasteful? Any other solutions? via /r/Parenting https://ift.tt/2HU48xh