Advanced: Rebound tenderness, board-like abdomen, vomiting, fever, obvious

Early: Persistent tenderness despite every effort to distract
  • Onset nausea/vomiting after progression of pain raises suspicion
High-Risk: elderly, debilitated, compromised hosts, portal hypertension
  • Peritonitis can be very subtle in these patients
  • Send such patients to ER for new onset abdominal pain

See posting Abdominal Pain – 3.