Should i go back to the hospital?

ok i went to the er about 4 days ago with really sharp pain around my belly on and in the lower right side of my stomach... i have been extremely nauseated and my pain is getting worse and i now have diarrhea.... the doc at the hospital said i had a uti and that she thought i might be in the beginning stages of appendicitis and thought for sure thats what i had but sent me home anyway..... now 4 days later i still have no relief.... should i go back and hope they do something... do you think it sounds like appendicitis???