Constipated 7 month old. Please help 😓

I started my son on solids 1 month ago.

Now he is constipated for 2 days. He tries to push the poop out but he can’t and it goes back in (I know tmi)

I have give him prune purée, more water, done bicycle legs, massaged his tummy, put some oil around rectum, but it doesn’t help.

How do I get the stuck poop out?

Please help. It hurts seeing him like this and nothing I do helps.