We had this issue at 3 weeks .... The pedi recommend the rectal thermometer and it worked !!! He pooped instantly !!! We used petroleum jelly on the tip ! Hope it helps 💓

Take his temp. But a towel under him though. My daughter would .. Release herself everytime I took her temp in the beginning lol. But it was messy

@tiffrae, Thank you

gross but massaging his anus. it will help him relax and he will poop. Also try bicycleing his legs for a few minutes.