Mommy, has anyone had this? Daughter is 1 year and 10 months old, we'v…

Mommy, has anyone had this? Daughter is 1 year and 10 months old, we've been treating her for two weeks now, but there have been no changes yet. From symptoms, irregular bowel movements (constipation), decreased appetite, also if she eats at 8 pm or later, she definitely vomits at night. The gastroenterologist prescribed Duflapak, probiotics, and according to the analysis, vitamin B12 is low. I'm exhausted from doing all of this, the child became very picky with food, appetite is either non-existent or wild ?