Sudden pain in the lower right quadrant of the abdomen is usually the first sign of appendicitis. The pain may also begin near the navel and travel to the lower right side. The pain often worsens if you cough, walk, or make other quick movements. Other symptoms of appendicitis include nausea, vomiting, loss of appetite, low-grade fever, constipation, diarrhea, abdominal bloating, and gas.