Proceed to your nearest emergency room if you are experiencing any of the following: sudden onset of severe abdominal pain especially if accompanied by fever and vomiting; vomiting especially if it is bilious; vomiting (green color); severe diarrhea associated with dehydration (symptoms of dehydration include dark-colored urine, decreased urine output, leg cramps, fatigue, dizziness, lightheadedness, or change in mental status); or sudden onset of significant rectal bleeding.