1. 5 month baby having foamy watery poop

My baby girl is 51 days old. She is having foamy watery poop since 2 weeks. 1st she had cold and cough for which I have given her salvin cold AF and mucolite after consulting my pediatrics. After that she has started having frothy watery poop. I thought that might be cough. But it didn't reduce. She had her 1st vaccination before a week, after that she was having green colour frothy watery poop 2 to 3 times a day. I asked the doctor who has vaccinated her, she asked me to give neopeptine drops. I consulted my pediatrics, he asked me to give Darolac syrup. But the vaccination doctor told me Darolac may cause constipation. Since yesterday my daughter is having watery and foamy poop but yellow colour. Please suggest which medication I should give her.