What is the initial workup for a patient presenting with stomach ache?

Initial Workup for Stomach Ache

The initial workup for a patient presenting with stomach ache should start with a thorough clinical evaluation including detailed history and physical examination, followed by appropriate laboratory tests and imaging based on the suspected diagnosis, with CT of the abdomen and pelvis with contrast being the most appropriate initial imaging for nonspecific abdominal pain, especially if accompanied by fever. 1

Clinical Assessment

• Determining the location of pain is a crucial starting point for guiding diagnosis and deciding on appropriate imaging methods 1, 2
• Evaluate vital signs to detect fever, tachycardia, hypotension, or tachypnea, which may indicate infection, bleeding, or other complications 1
• Look for alarm signs such as severe pain, sudden onset, high fever, abdominal distension, rebound tenderness, or positive Murphy's sign (pain when pressing the right upper quadrant) 1
• Assess for signs of peritonitis, which may indicate intestinal ischemia or perforation 3
• Note that severe abdominal pain out of proportion to physical examination findings should raise suspicion for acute mesenteric ischemia 3

Laboratory Tests

• Complete blood count to evaluate for leukocytosis, which may suggest infection or inflammation 1
• Beta-hCG test for all women of childbearing age before proceeding with imaging 1
• Consider metabolic panel, liver function tests, amylase, and lipase to evaluate for metabolic disorders, liver disease, and pancreatitis 3
• D-dimer and lactate levels if mesenteric ischemia is suspected 3

Imaging Based on Pain Location

• Right upper quadrant pain: Abdominal ultrasound is the most appropriate initial imaging method 1, 3
• Right lower quadrant pain: Abdominal ultrasound is recommended as the initial imaging method, particularly for suspected appendicitis 1
• Left lower quadrant pain: CT of the abdomen and pelvis with contrast is recommended, especially for suspected diverticulitis 1, 3
• Nonspecific abdominal pain: CT of the abdomen and pelvis with contrast is the optimal choice, especially if there is fever or suspicion of serious illness 1, 3
• Epigastric pain: Consider upper GI series with fluoroscopy if gastritis, peptic ulcer disease, or GERD is suspected 3

Imaging Based on Suspected Condition

• Acute cholecystitis: Abdominal ultrasound 1
• Acute appendicitis: CT of the abdomen and pelvis with contrast (consider ultrasound first in young patients to minimize radiation exposure) 1
• Kidney stones: Non-contrast CT of the abdomen and pelvis 1
• Bowel obstruction: CT of the abdomen and pelvis with contrast 3
• Mesenteric ischemia: CT angiography of the abdomen 3

Important Considerations

• Plain abdominal radiography has limited diagnostic value in evaluating acute abdominal pain and should not be the initial imaging test of choice 4, 3
• In women of childbearing age, consider gynecologic conditions such as ectopic pregnancy, ovarian torsion, or pelvic inflammatory disease 1
• In older adults, symptoms may be atypical and require more thorough evaluation, even if laboratory tests are normal 1, 5
• Consider using ultrasound as the initial imaging method for suspected acute appendicitis before proceeding to CT, especially in young patients, to minimize radiation exposure 1
• For patients with chronic undiagnosed abdominal pain, consider functional disorders after excluding organic causes 6

Red Flags Requiring Urgent Evaluation

• Severe pain out of proportion to physical findings (suggests mesenteric ischemia) 3
• Signs of peritonitis (rigid abdomen, rebound tenderness) 3
• Hemodynamic instability (suggests bleeding or sepsis) 3
• Fever with abdominal pain (suggests infection or abscess) 3
• Abdominal distension with vomiting (suggests bowel obstruction) 3