Is Laboratory Data Helpful in the Workup of Chronic Abdominal Pain?

Abstract

The selective use of laboratory testing may help determine the acuity of a chronic abdominal complaint, detect previously overlooked causes of a chronic abdominal pain syndrome, or reveal a new disease process unrelated to the chronic condition. Choice of testing should focus on the specific issues being investigated. Pregnancy testing in female patients of childbearing age and urinalysis for pyuria (infectious or sterile) or hematuria may demonstrate or rule out important diagnoses. Inflammatory markers such as the white blood cell count (WBC) and C-reactive protein (CRP) are of low discriminatory value as a screening test in patients with abdominal pain. Leukocytosis is only seen in about half of all patients with acute abdominal pathology, and a WBC or CRP within reference range does not rule out an urgent condition. An elevated lactate, a marker for disease severity, has high sensitivity for mesenteric ischemia. When evaluating the patient with chronically recurring abdominal pain, the emergency clinician is advised to make selective use of high-yield laboratory data and avoid a “shotgun” approach.