<s>[INST] Hi, my 1 and half year old Grandson has been vomiting when he lays down to sleep. He only ever brings up liquid but with yellow phlegm and white frothy phlegm. He has also had very bad bouts of constipation with very large hard to pass stools. What could this be please. [/INST] HiExact diagnosis is only possible by thorough evaluation and clinical assessment by Paediatrician. Going by description of symptoms Hirschsprung's needs to be ruled out.Do write to me directly for detailed discussion </s>