Acute abdomen is defined as severe localized or generalized abdominal pain with abdominal rigidity.[1] It is less than 24 hours in duration and may require surgical evaluation and intervention.
Acute abdominal pain usually has a duration of several days; subacute abdominal pain has a duration of more than several days but less than 6 months.
Chronic abdominal pain has a duration of more than 6 months.[2]
↑Sleisenger, Marvin H.; Feldman, Mark; Friedman, Lawrence S. (Lawrence Samuel); Brandt, Lawrence J. (2010). Sleisenger and Fordtran's gastrointestinal and liver disease : pathophysiology, diagnosis, managemen. Philadelphia , PA: Saunders/Elsevier. ISBN1-4160-6189-4.