Utility of clinical symptoms versus laboratory tests for evaluation of acute gastroenteritis.

Our purpose was to find the utility of laboratory tests in emergency ward evaluation of patients with gastroenteritis. Medical records of 163 adult cases were retrospectively reviewed. Blood laboratory tests were drawn in 116 cases, 78 had at least one abnormality. Urine tested ketone-positive in 15 of 116 cases. One hundred fifteen were treated with intravenous fluids, 20 with antibiotics, and 4 were admitted. Fifty-eight stool cultures were sent, and 13 yielded enteric pathogens. Cultures from patients with fever or symptoms of long duration had higher yields (57% vs 11.3% and 38.1% vs 0%, P < 0.001, respectively), and when combined had sensitivity of 100% and specificity of 65%. There was no association between abnormal blood laboratory results, intravenous hydration, and antibiotic treatment with the stool culture being positive or with the patient being hospitalized. Laboratory tests are used often, but are very seldom contributory for evaluating domestically acquired gastroenteritis.