Objective: To assess the value of plain abdominal radiographs and of data from the medical history and physical examination in the diagnosis of acute abdominal pain in general and of bowel obstruction in particular.
Design: Prospective study.
Setting: 4 university and 2 community hospitals, Germany.
Subjects: 1254 patients with acute abdominal pain lasting less than 7 days, and with no history of abdominal injury including surgery.
Interventions: Standardised and structured medical history and physical examination, study of results of plain abdominal radiographs.
Main outcome measures: Positive predictive value and sensitivity of clinical variables and abdominal film with respect to the diagnosis at discharge.
Results: 48 patients (3.8%) had bowel obstruction. 704 patients (56.1%) had plain abdominal films taken at the time of initial presentation. 111 studies (15.8%) showed important findings leading to diagnosis or immediate treatment, 455 (64.7%) showed unimportant or no findings. In 138 (19.6%) results of films were not reported. 16 of 45 single variables were of help in diagnosing bowel obstruction. The six with the highest sensitivity were distended abdomen, increased bowel sounds, history of constipation, previous abdominal surgery, age over 50, and vomiting. If only patients presenting with any two of these symptoms had had radiographs taken, 300 (42.6%) could have been avoided without loss in diagnostic accuracy.
Conclusion: A considerable number of plain abdominal films taken for patients with acute abdominal pain could be avoided by focusing on clinical variables relevant to the diagnosis of bowel obstruction.