There's the slow roll approach of having him ask for a diaper whenever he needs to poop—then having him poop while on the toilet wearing the diaper. Then creating a special diaper (you cut a hole) that you have him use while sitting on the potty. Finally, you remove the diaper.
We picked up this book: It Hurts When I Poop! A Story for Children Who Are Scared to Use the Potty. And we had to remove all diapers/pull-ups. We said we ran out. We also had a poop party (from the book) after our kid pooped on the potty like 5 days in a row.
Thanks for the camaraderie!
We used this book: https://smile.amazon.com/Hurts-Story-Children-Scared-Potty/dp/1433801310
For a while we tried the 'you can use the potty or get a pull-up' approach. This led to much more relaxing days, but he always chose pull-up. It took a turn for the worse when he used the pull-up for everything (pee and poo) and then not putting the pull-up on correctly and peeing his pants.
Trying to drop it/ignore it led to more rashes, but that was earlier. It was my intention last night to not talk about it at all, but he brought it up unfortunately. Me being the bigger person, I should have just ignored it and moved on but then I spent too much time talking with him about it.
The reward system isn't just for poop/pee. It was at one point, but we did scrap that one. It's also to help teach him about saving/spending so he gets 'carrots' for helping around the house too (setting the table, folding towels, etc.). Maybe we just do that instead of poop/pee earnings?
oh my god we have the same fucking problem with our daughter. forever now it feels like. (but seriously she's had constipation problems since she started solids it's crazy). Anyways. Miralax. every day, one tablespoon. She gets it first thing in her morning milk. It's not harsh and just uses her body's natural water to go to her poop. The muscles in their intestines get stretched out when they hold it in too long so when she gets constipated from holding in her shit we have to give her the miralax for a month to get those muscles back to being tight.
This book also is a fucking life saver, we got it last week after we had to give her a suppository for the firs time. (which was not as horrible as i thought it would be btw). It Hurts When I Poop! a Story for Children Who Are Scared to Use the Potty https://www.amazon.com/dp/1433801310/ref=cm_sw_r_cp_api_3owYybFAM2XKJ Now when i see her trying to hold it in i kneel down net to her and say "hey are you being the boss of your own body? say get out of my body poo-poo!" if she hates shitting so much she should get it out!
A couple things:
Talk to your doctor. Our son also had trouble with it hurting when he pooped. And as a result he tended to hold it and it made him very constipated. We had to put him on Miralax for awhile to help keep things moving.
We also bought a book called "It hurts when I poop" and read it together and talked about it a few times. And that seemed to help him understand what was happening and why it's important to go when you feel like you need to.
This helped my daughter SO much It Hurts When I Poop! a Story for Children Who Are Scared to Use the Potty https://www.amazon.com/dp/1433801310/ref=cm_sw_r_cp_api_i_2AAoFbV2D01ZM
Or this timeless classic: https://www.amazon.com/dp/1433801310/ref=cm_sw_r_cp_apa_i_ou0nFbKDS5YWG
If your kid likes reading books (well, being read to, I guess), try this book:
https://www.amazon.com/dp/1433801310
It did wonders for us when we were potty training our oldest. It also has some helpful tips for parents in the back, too!