Green poop

My son is 5 weeks old. I was induced at 37 weeks gestation due to IUGR. He was 5lbs 1 oz and was in the NICU for 5 days for low blood sugars. I am exclusively pumping and feeding him bottled breast milk no formula. He was having normal yellow poops and weight gain has been great. But he was having a bit of acid reflux an gas so I decided to cut dairy. It’s been 2 weeks and I have not noticed a significant difference in his acid reflux and now his poops are green and sometimes mucousy. Should I go back to eating dairy? I will be calling his Pedi today but just wanted to see if anyone has experienced this.