Reflex pains often get physicians into trouble. Operations on the abdomen have been performed by wise physicians for reflex pains in pneumonia; the symptoms being pain, tenderness, gas distention, temperature, frequent respiration, but lacking the pulse of peritonitis. Extensive intercostal neuralgia may be mistaken for abdominal affection; also for lung disease. The intercostal nerves end in the abdominal wall.

Abscess in the wall of the abdomen may be mistaken for peritoneal disease. More than forty years ago a case of abscess of the abdominal wall came into my hands, after several good physicians had named the disease peritonitis and given an unfavorable prognosis.