What Causes Recurring Episodes Of Vomiting And Diarrhoea In A Child?

my grandson age 7 haa been throwing up every hour since about 10pm it is now almost 4 he wakes up aind of crying then kind of cough and throws up it is vey foam like and mucus ey he he just t gotn over cold he r tonight befor he got sick he was swimming for about 3 hour he does not have a fever he also had diarehea