Hi, It seems your grand son is having viral diarrhea. Once it starts it will take 5-7 days to completely get better. Unless the kid s having low urine output or very dull or excessively sleepy or blood in motion or green bilious vomiting. You need not worry. There is no need to use antibiotics unless there is blood in the motion. Antibiotics might worsen if unnecessarily used causing antibiotic associated diarrhea. I suggest you use zinc supplements (Z&D drops 1ml once daily for 14 days) & ORS (Each small packet mixed in 200ml of potable water and keep giving sip by sip) as hydration is very important and crucial part of treatment. If there is vomiting you can use Syrup Ondansetron (as prescribed by your pediatrician). Regarding diet - Avoid fruit juices as they might aggravate diarrhea. You can give zinc supplements & ORS apart from normal vegetarian porridges & soups. Hope I have answered your query. Let me know if I can assist you further.