++
The term “acute abdomen” collectively denotes any sudden, spontaneous, nontraumatic, severe-onset abdominal pain, typically of less than 24 hours in duration. The acute abdomen requires urgent assessment, as well as rapid and specific diagnosis because several etiologies demand urgent or emergent operative intervention. Because there is frequently a progressive underlying intra-abdominal disorder, undue delay in diagnosis and treatment may adversely affect patient outcome. Therefore, understanding the clinical presentation in the context of associated laboratory and diagnostic imaging findings and the various facets of preoperative evaluation of acute abdomen is essential.
++
The approach to a patient with an acute abdomen must be systematic and thorough, yet efficient to minimize delay. An acute abdomen should be suspected even in a patient with only mild or atypical presentations. Increasingly, certain patient populations present with atypical complaints, including immunocompromised, elderly, and bariatric patients. The complete history and physical examination often suggest the probable cause(s) (Table 25–1), allow for timely formation of a differential diagnosis, and judicially guide the choice of appropriate initial diagnostic studies.
++++
Depending on the degree of clinical suspicion and status of the patient, the clinician must then decide if in-hospital observation is warranted, if additional tests are needed, if early operation is indicated, or if nonoperative treatment and hospital admission would be more suitable. If unclear or when in doubt, it is always appropriate to be a little aggressive and pursue additional relevant tests, if needed. This chapter provides important insights and a useful framework to efficiently diagnose and manage a patient with an acute abdomen.
++