i have a son 4mos, old whose suffering diarrhea, he has a watery stool, yelllowish-greenish in color,, his pediatrician gave him a contrimoxazole for 7 days treatment,, and a hidrasec for infant.. but i worry because its as if hes not getting better,,though hes under medication,, my son has a diarrhea for 2 weeks now,, what should i do?