You probably are suffering from toxic diarrhea most commonly causd by organism Staphylococcus aureus. It starts within 4-24 hours of eating infected food which usually is an inadequately cooked one. Despite the severity of symptoms it s usually self limiting and you only need to take adequate fluids to avoid replacement by an IV Drip. The regular Oral Rehydration Solution that contains adequate salt and sugar is available widespread. To avoid any complication that may include shock and low Blood Pressure please use tab Flagyl 500 mg one tab twice a day and tab Ciprofloxacin 500 mg one tab twice a day plus tab Domperidone or Metoclopramide [the latter for vomiting or vomiting sensation] sos for 5 days if the symptoms persist. These medications are for other microorganisms causing Gastroenteritis but should be used with caution and only after toxic diarrhea and vomiting are excluded. This is to avoid development of resistant strains of these other organisms. Hope this helped. God bless.