I have been having a runny tummy and been vomiting since last night. ?

Depends on severity: Normal, healthy, young adults can get the stomach flu or food poisoning symptoms from time to time. A patient will usually vomit until his stomach is all empty, which is why it is important to NOT eat or drink anything for a few hours afterwards. After that, a common treatment is small amounts of Pedialyte or broth, maybe 1 ounce every half hour while awake. A primary doctor can evaluate and help.