Constipated baby

Help!

My son just turned 5 months and has been constipated for nearly a month. We’ve been to the pediatrician twice over it. The first visit they told us since he had pooped that day (after going 5 days with nothing) to use gas drops after every feed. Then a couple weeks later he pooped formed balls so I took him in again and she prescribed glycerin suppository as needed but told me he probably wouldn’t need them everyday because he can go a while without bowel movements. She told us to give 0.5oz-2oz off pear or prune juice not diluted or rental stimuli when needed.

He’s still backed up after a couple weeks and now I feel like I’m either pumping him full of sugars or checking his temp rectally almost daily because he grunts so hard his face gets red. I need some alternatives. Honestly thinking about getting a second opinion from a different ped also!

What products do you all use? Thanks in advance!!!