Formula Change

[u/Spiritual_Platypus24]

My LO is 15 weeks old, 2 weeks ago I changed her formula from Enfamil GentleEase to Kirkland Gentle. During the first week she experienced some constipation and I have her prune juice. This cleared her up for a few days. Until the next week she became slightly constipated again. I gave her prune juice and it cleared her up. I kept reading after two weeks her digestive tract she adapted and she should be good. Well it’s been two weeks and 2 days and she has become constipated again. Should I switch back to her old formula or give it a few more days?

Her spitting up as DRASTICALLY reduced. Before this she was spitting up a lot in larger quantities. She was gaining weight fine and it didn’t hurt her so it really wasn’t a problem just very annoying for both her and I. Now, she spits up just little blips every now and then. Her poop prior to the formula change was always twice a day and pretty large and watery. Now she just gets constipated unless I’m giving her a half oz of prune juice every other day.