What is the initial workup for a patient presenting with abdominal pain and bloating?

Initial Workup for Abdominal Pain and Bloating

The initial workup for abdominal pain and bloating should include a focused history, physical examination, basic laboratory tests, and targeted imaging based on pain location, with ultrasonography recommended for right upper quadrant pain and CT scan for right or left lower quadrant pain. 1

Focused History

When evaluating a patient with abdominal pain and bloating, obtain the following key information:

• Pain characteristics:

  • Location (quadrant-specific)
  • Onset (sudden vs. gradual)
  • Duration and pattern (intermittent vs. constant)
  • Quality (crampy, sharp, dull)
  • Radiation
  • Aggravating/alleviating factors

• Associated symptoms:

  • Nausea/vomiting
  • Changes in bowel habits (constipation, diarrhea)
  • Last bowel movement and character
  • Passage of gas
  • Fever
  • Weight loss

• Relevant history:

  • Previous abdominal surgeries (85% sensitivity for adhesive small bowel obstruction) 1
  • History of diverticulitis or chronic constipation
  • Rectal bleeding
  • Unexplained weight loss (suggestive of malignancy)
  • Medication use

Physical Examination

• Vital signs: Temperature, heart rate, blood pressure, respiratory rate
• General appearance: Signs of distress, dehydration
• Abdominal examination:
  • Inspection: Distention, asymmetry, visible peristalsis, surgical scars
  • Auscultation: Bowel sounds (hyperactive, hypoactive, absent)
  • Percussion: Tympany (suggests gas), dullness (suggests fluid/mass)
  • Palpation: Tenderness (location and severity), guarding, rebound tenderness, masses
• Rectal examination: For masses, tenderness, fecal impaction, occult blood

Laboratory Testing

• Basic tests for all patients:

  • Complete blood count (CBC)
  • Basic metabolic panel
  • Urinalysis
  • Stool Hemoccult test 1

• Additional tests based on clinical suspicion:

  • Liver function tests (for right upper quadrant pain)
  • Lipase/amylase (for suspected pancreatitis)
  • Pregnancy test in women of reproductive age 1
  • Erythrocyte sedimentation rate (ESR) in younger patients 1
  • Stool for ova and parasites (in cases of diarrhea) 1

Imaging Studies

Imaging selection should be based on the location of pain and clinical suspicion:

• Right upper quadrant pain: Ultrasonography is the initial imaging test of choice 1
• Right or left lower quadrant pain: CT scan with contrast media 1
• Diffuse/nonlocalized pain: CT is typically the imaging modality of choice if serious pathology is suspected 1
• Conventional radiography: Limited diagnostic value for most abdominal pain but may be useful for suspected bowel obstruction, perforated viscus, or foreign bodies 1

Special Considerations

Suspected Bowel Obstruction

If bowel obstruction is suspected based on symptoms (constipation, abdominal distention, vomiting):

• Conventional radiography may be appropriate as an initial study 1
• CT scan is more definitive and can identify the cause and location of obstruction 1

Suspected Irritable Bowel Syndrome (IBS)

If symptoms suggest IBS (chronic abdominal pain, bloating, altered bowel habits), consider:

• Limited diagnostic workup if Rome II criteria are met 1
• Screening tests to rule out organic disease
• Evaluation for alarm features (weight loss, nocturnal symptoms, family history of IBD or cancer) 1

Suspected Intra-abdominal Infection

For suspected intra-abdominal infection:

• Step-up approach beginning with clinical and laboratory examination 1
• Progress to imaging based on clinical findings 1
• Consider ultrasonography first, followed by CT if results are inconclusive 1

Diagnostic Algorithm

1. Assess severity and stability: Determine if patient requires immediate surgical intervention (peritoneal signs, hemodynamic instability)

2. Localize pain and direct workup accordingly:

   • Right upper quadrant: Ultrasonography first
   • Right or left lower quadrant: CT with contrast
   • Diffuse/nonlocalized: CT if serious pathology suspected

3. Consider common diagnoses based on location:

   • Right upper: Cholecystitis, hepatitis, peptic ulcer disease
   • Right lower: Appendicitis, ileitis, ovarian pathology
   • Left upper: Gastritis, pancreatitis, splenic disorders
   • Left lower: Diverticulitis, colitis, ovarian pathology
   • Periumbilical: Small bowel obstruction, early appendicitis
   • Diffuse: Gastroenteritis, bowel obstruction, peritonitis

4. Rule out functional disorders after excluding organic pathology:

   • Consider IBS if Rome II criteria are met 1
   • Consider functional bloating if no structural abnormalities are found

Common Pitfalls to Avoid

• Failing to obtain pregnancy testing in women of reproductive age
• Overreliance on conventional radiography, which has limited diagnostic value for most abdominal conditions 1
• Overlooking bowel injury, which is one of the most commonly missed abdominal injuries on initial CT 1
• Neglecting to consider extra-abdominal causes of pain (thoracic, pelvic, or abdominal wall origins)
• Assuming bloating is always functional without adequate workup for organic causes

By following this systematic approach, clinicians can efficiently evaluate patients with abdominal pain and bloating, ensuring appropriate diagnosis and management while minimizing unnecessary testing.