The basic part of treatment is to avoid Dehydrtion, this is achieved via sips of oral rehydration therapy (ORS) or chicken and beef soup but in severe cases intravenous fluids are given in the hospital.
Fruit juice and frizzy drinks are avoided as they can worsen disease in children. If the child is vomiting allow small sips till well tolerated then graduate to bland diets like pap and eko without milk. Avoid sweets, coffee and milk products.

It could be Acute or Chronic Diarrhoea.
Acute Diarrhoea :- this occurs suddenly and usually last a few days to weeks but resolves on its own.
Chronic Diarrhoea :- onset is not sudden and it usually lasts well over two weeks, this needs urgent medical attention to find the underlying cause and initiate treatment with the dreaded complication of both being Dehydration of varying degrees. Prevention and treatment should commence fast especially in children to avoid fatalities.

Most likely Diarrhoea. This is having frequent loose watery stools. It occurs when the fluid cannot be absorbed from the contents of an individuals bowel or when extra fluid is secreted into the bowel causing watery stool. Usually it could be a symptom of bowel infection called Gastroenteritis which can be caused by some harmful micro organisms that may result from food poisoning I.e drinking contaminated water or eating contaminated food.