Baseline Workup for Abdominal Pain

Initial Clinical Assessment

The American Academy of Family Physicians recommends evaluating pain characteristics (location, onset, duration, quality, radiation, aggravating/alleviating factors) to help narrow differential diagnosis 1, 3
Assessing for associated symptoms such as fever, nausea, vomiting, diarrhea, or constipation may suggest specific etiologies 3
Documenting vital signs, as fever may indicate infection or inflammation, and hemodynamic instability may suggest emergent conditions like hemorrhage or sepsis 4
Performing a complete abdominal examination including inspection, auscultation, percussion, and palpation to identify specific findings such as distension, tenderness, guarding, or rebound tenderness 1

Complete blood count can assess for leukocytosis (suggesting infection or inflammation) 5
C-reactive protein can be used as a marker of inflammation 5
Liver function tests and hepatobiliary markers are especially important for right upper quadrant pain 5
Serum electrolytes, creatinine, and blood urea nitrogen can assess renal function 5
Pregnancy test is recommended for all women of reproductive age 1
Stool analysis and culture, and C. difficile toxin testing may be appropriate in certain cases 5

The American College of Radiology recommends selecting imaging modality based primarily on the location of pain 1, 2
For right upper quadrant pain, ultrasonography is the initial imaging test of choice 1, 4
For right or left lower quadrant pain, CT scan is recommended 1, 6
For diffuse or nonlocalized abdominal pain, CT scan with IV contrast is preferred 3, 6
Conventional radiography (plain abdominal X-rays) has limited diagnostic value in most cases of abdominal pain and should not be routinely used 1
MRI is an alternative for pregnant patients or those who cannot undergo CT scanning 7
Point-of-care ultrasound may be useful for specific conditions when expertise exists 5

In elderly patients, atypical presentations are common, and laboratory tests may be normal despite serious infection 3
In immunocompromised patients, typical signs of abdominal sepsis may be masked 3
For pregnant patients, ultrasound should be the first-line imaging, with MRI preferred over CT if additional imaging is needed 7

Relying solely on laboratory tests without appropriate imaging, as many conditions require imaging for definitive diagnosis 3