Evaluation of Abdominal Pain

Initial Clinical Assessment

The American College of Radiology recommends CT of the abdomen and pelvis with IV contrast as the preferred initial imaging study for acute nonlocalized abdominal pain, as it changes the leading diagnosis in 51% of patients and alters admission decisions in 25% of cases 1
For patients with right upper quadrant pain, suspect acute cholecystitis, hepatobiliary disease, or cholangitis, according to the American College of Radiology and American Family Physician 2, 3
For patients with right lower quadrant pain, appendicitis is the critical diagnosis to exclude, and consider ectopic pregnancy in women of reproductive age, as suggested by the American Family Physician 3
Tachycardia is the most sensitive early warning sign of surgical complications and should trigger urgent investigation, even before other symptoms develop, as recommended by the American College of Radiology 5

The American College of Radiology suggests ordering a complete blood count (CBC) to assess for leukocytosis indicating infection or inflammation, and a comprehensive metabolic panel (CMP) including liver function tests to evaluate hepatobiliary pathology 5, 6
Serum lipase is recommended for suspected pancreatitis, and urinalysis to evaluate for urinary tract infection or nephrolithiasis, according to the American College of Radiology 6
Beta-hCG testing is mandatory in all women of reproductive age before proceeding with imaging to rule out ectopic pregnancy, as recommended by the American College of Radiology 4, 5, 6

For right upper quadrant pain, ultrasonography is the initial imaging test of choice for evaluating acute cholecystitis and hepatobiliary disease, according to the American Family Physician and the American College of Radiology 3, 6
For right lower quadrant pain, CT of the abdomen and pelvis with contrast is the initial imaging study of choice for suspected appendicitis, as recommended by the American Family Physician and the American College of Radiology 3, 6
For nonlocalized or diffuse abdominal pain, CT of the abdomen and pelvis with IV contrast is the preferred imaging option, due to the broad differential diagnosis and need for rapid imaging, according to the American College of Radiology 1, 7

Failing to obtain β-hCG testing in women of reproductive age before imaging can delay diagnosis of ectopic pregnancy, which is a life-threatening condition, as warned by the American College of Radiology 4
Conventional radiography has limited diagnostic value in most patients with abdominal pain and should not be routinely ordered, according to the American College of Radiology and the Journal of the American College of Radiology 2, 6, 7

Women of reproductive age should always be considered for gynecologic conditions, including ectopic pregnancy, ovarian torsion, or pelvic inflammatory disease, and CT of the abdomen and pelvis with contrast is most appropriate for pelvic pain, as recommended by the American College of Radiology 4, 5
Elderly patients may have atypical symptoms and require more thorough evaluation, even if laboratory tests are normal, and have a higher likelihood of malignancy, diverticulitis, and vascular causes, according to the American College of Radiology and the Journal of the American College of Radiology 1, 2, 4