CHILD KEEPS POOPING HIS PANTS

Hi all! I have a (5m) child who is going through a very long phase of potty-training regression. It started out as “accidents” approx. 6 months ago, but upon further investigation, he is simply pooping his pants out of convenience. I had a talk with him about WHY it is happening because he insisted he just didn’t make it to the toilet in time but he confessed he just poops his pants and then dumps it out in the toilet and goes on about his day. He cannot be bothered to go and sit on the toilet and go poop. He has also pissed on his floor right before bed time because he was “feeling lazy.” Most of the time, he was doing something that had his full attention- watching a show, playing outside, etc.- so I have limited the time that we do tasks down to 45 mins and have him try to go potty in-between. All went well the first day but on the second day he cried and whined about having to go “try” (I have him sit there for 5 mins- he is unaware that they are timed) and he didn’t poop at all. This morning, he pooped his pants again while we were standing outside and right after I had him try to go. He lies and covers it up and promises he wont do it again but its feeling like he will say whatever to just continue on and go about his day.

I have tried positive reinforcement. I have tried sticker charts. I am getting to a point where I am willing to try anything because I do not want to go back to giving him two baths a day because he wants to poop his pants.

At first I did suspect sexual assault so I have asked plenty of questions, with reassurance that nobody will get in trouble, and he has said repeatedly that nobody his touching his private parts and he is not being forced to touch or look at anybody else’s.

He is also a GREAT kid with zero problems socially. He is always so positive and upbeat and the first one to tell someone “good job” or “you are doing awesome”. He does not lie outside of going to the bathroom. It is very weird and strange behavior. The only issues their father and I have is that he shows VERY strong signs of early ADHD (his father has it and is very adamant about him never going on medication for it) and I’m wondering if that has anything to do with it?

I am so so lost please help me): This is so frustrating and I simply cannot figure out a way to get him on board with going poop on the toilet. He starts kindergarten soon and I don’t want him to be known as the kid who smells like poop/poops his pants.

TL;DR- Can’t figure out how to convince 5 y/o that it is more convenient to go poop on the toilet instead of his pants.