o Abdominal pain and gastrointestinal bleeding may occur at any time during the disease;severe abdominal pain may even suggest-or portend-an acute surgical abdomen.Paralytic ileus may occur. Vomiting,rebound tenderness,and distension are other manifestations. ⚫ Abdominal pain and gastrointestinal bleeding may occur at any time during the disease; severe abdominal pain may even suggest- or portend- an acute surgical abdomen. Paralytic ileus may occur. Vomiting, rebound tenderness, and distension are other manifestations