Hi there, With fever and pain in the lower right abdomen, the first thing that I would need to consider is acute appendicitis. It can sometimes come with vomiting and diarrhoea as well, due to the irritation of the surrounding bowels. Sometimes the pain can paradoxically feel better temporarily after the appendix ruptures before the surrounding infection sets in. If you are still having the pain, I would advise you to get yourself to the hospital to confirm the diagnosis. Food poisoning usually comes with colicky kind of pains that come and go and is more central, rather than the constant pain that you are experiencing. The other possibility is urine infection, but this also usually does not cause a fever unless the infection has progressed to the kidneys, which is felt as pain at the mid-back. When you see your doctor, he or she would be able to examine you to see if there is significant tenderness at the area involved. If unsure, they may run some investigations like blood counts or an ultrasound of the abdomen to look for other signs suggestive of appendicitis. Get yourself to a hospital as soon as possible. Hope this helps, and all the best to you. Regards, Dr. Teh