The introduction of standardised data-collection forms and computer-aided diagnosis has been found to be associated with improved diagnosis and management of patients with acute abdominal pain. The mechanism by which such benefits accrue has been the subject of some controversy. Detailed analysis of 5193 patients from one hospital shows that the major benefit from such diagnostic aids was the accurate early diagnosis of non-specific abdominal pain by senior house officers in the accident and emergency department; this in turn led to fewer admissions and fewer operations with negative findings. Clinical data about patients with acute abdominal pain should be recorded on structured information sheets by junior doctors and early positive diagnosis should be encouraged before decisions affecting the patient's management are made. Improved computer support may confer further benefits.