If you have had very liquid diarrhea since Monday the 20th of July around 10pm, the best thing to do is to reduce intake of irritating foods, drink plenty of water, and get rest. It could be a viral gastroenteritis in your intestines. Avoid taking products like Imodium™ to allow the body to eliminate the irritant naturally. You could also try taking probiotics to speed up the return to normal bowel movements. If you develop a fever or if the diarrhea persists by next Monday, it would be best to consult a doctor.