Failing to clean out our toddler with Miralax, help?

I’m so tired of this…. Our daughter (2 years old) has been constipated for a long time and latest 6 months she has been on Miralax. 18-24g corresponding to 1.5g-2g/kg. Due to constant soiling and small poops we have been trying to do a clean out to get rid of the back log. We have done two days with 36g and today 48g Miralax with no success. Just the same small poops that keep coming. Any advice, has anyone experienced that the clean out would work with a little bit more time??? 😔 our ped says to continue over the weekend but I feel bad pushing so much meds into her which doesn’t seem to help