Confused

My baby turned 4 months a week ago. He went for his well check today and our biggest concern was he starting to have some constipation-- the longest he'll go without pooping is 2 days.

Today would've been the 4th day since his last poop but the doctor reassured me it's normal. His belly is soft and he doesn't seem in distress however he made his pooping sounds for 5-10 seconds for the past 2 days without any poop coming out. Still, she said it's okay.

She said to try watered apple juice if it persists and then my baby started pooping right then and there-- and it was hard and ginormous. 😱😱 I guess at this time she believed me.

Anyways--- she said I could also try baby food prunes, 1 tablespoon a day. This literally confuses the heck out of me. Did she mean like the pureed prunes? Is he even ready for that? 🤔🤔

Any of you did this? Or maybe let me know what your understanding is as to what she said??