What does tenderness in the right side of the stomach next to the belly button, low grade fever and vomiting mean?

Abdominal pain: I do not know how long this has been going on, but usually this indicates a gastritis or stomach infection. I would stick with clear fluids for a day. This can be signs of an appendicitis in a early stage so keep an eye on it. If it persists or if the pain migrates to your lower abdomen and is associated with pain on movement get checked.

R/o appendicitis: Could be other serious conditions contact your doctor or consider going to urgent care or er.

Appendicitis?: This could be many different things, but you need to go and see a doctor asap, even if it means going to an er. This has the potential to become extremely serious if not tended to rapidly. Go and be evaluated.

Causes of symptoms: Thanks so much for your question. The constellation of symptoms you are having could possibly be appendicitis, infectious intestinal disease, or other problems. I suggest you see a doctor as soon as possible. If the symptoms become quite severe, where you have severe pain, unable to eat, unable to keep fluids down, or vomiting blood, you should be seen at the emergency department. Good luck.

Watch out for Append: Unless you have it already out(removed) it could be your appendix getting inflamed. So if the symptoms get any worse or you have real fever(>100 degrees), you should get a medical examination and a CBC done to be sure you do not have infection in your kidney or in your appendix.