Following the initial correction of hypovolemia, fluid requirements should barely exceed that needed for maintenance. Fluid sequestration into the peritoneal cavity (third spacing) will cease. The signs of peritonitis, such as muscle rigidity and tenderness, will begin to resolve. Indeed, if such beginning resolution is not apparent within 12 hours, the diagnosis of self-sealed perforated ulcer should be questioned. There is always the remote possibility that a patient with a documented ulcer in the duodenum, diffuse peritonitis, and pneumoperitoneum, but without leakage on a gastroduodenogram, may have perforated another lesion of the gastrointestinal tract.