IN THE presence of diarrhea the differential diagnosis of acute appendicitis from enteritis is difficult. Even in the absence of diarrhea acute appendicitis may be mistaken for enteritis because both diseases begin with pain not unlike a sensation of impending diarrhea and because the physical and the laboratory findings may be almost identical in the two diseases during the early stage (cases 2 and 3).
Ultimately, the diagnosis may depend largely on the results of an orderly and detailed analysis of the history of the case, which brings out points 1 to 4 listed in table 1. The differential points are as follows: The first pain of acute appendicitis is persistent, and that of enteritis is intermittent. The first pain in both ailments is associated with a bowel urge,1 but pain persists despite defecation in the early stage of acute appendicitis whereas in enteritis defecation relieves the pain completely
KEYES EL, COOK MM. DIAGNOSIS OF ACUTE APPENDICITIS IN THE PRESENCE OF DIARRHEA. Arch Surg. 1946;52(4):429-444. doi:10.1001/archsurg.1946.01230050436004