Anyone give baby prune juice?

Katie

My son went a week without pooping two weeks ago. The doctor said if he does a week without two bowel movements I should give him an oz of prune juice. He just went a week again (I’m wondering if this is just his new normal) so I tried to give him prune juice and he hated it! I maybe got him to take in a quarter of the oz if that (I tried with a bottle and a medicine syringe). Anyone have any tips?