acute rescue

A telephonic conversation:-

Mother- Doctor my baby(male) of 2 yrs has been passing loose stools since morning, were not that frequent , but today since morning passed absolutely watery stools, almost every 10-15 minutes, he is now quite dull, pl tell me what remedy from my box of homoeopathic medicines should I give him? 2 days ago, I had given him china 30 and he was quite okay after that, do I need to repeat China ?

After asking few more questions, child rescued with a single dose of a single remedy, what do u think were the questions asked and what could be the remedy after the mother answered those questions.