Diarrhea since monday and he still hasnt stop?

Diarrhea: If it's a viral infection, rest. Drink adequate fluids. Don't eat harsh roughage foods which are undigestable. Take kaopectate or imodium if diarrhea isn't improving. See MD if not better after several days and a stool culture will be done to look for pathogenic bacteria or parasites. Bleeding from rectum or vomiting would be concerning for serious illness and need for examination.