Abdominal pain is one of the broadest CCS chief complaints you will face on Step 3. The differential diagnosis is enormous, the management depends heavily on the anatomic location and acuity, and there are several diagnoses that require emergent surgical intervention. This article gives you a systematic approach that works for any abdominal pain case — ER, clinic, or floor.
The First 60 Seconds: Every Abdominal Pain Case
Immediate orders:
1. IV access
2. NPO (make the patient nothing by mouth — critical if surgery may be needed)
3. Vital signs + pulse oximetry
4. Cardiac monitor (if hemodynamically unstable)
5. Pain management — do NOT withhold pain control. Morphine or ketorolac does not mask surgical findings, and the patient needs symptom management.
Universal rule for all women of childbearing age: Order a urine pregnancy test (beta-hCG) immediately, regardless of the suspected diagnosis. An ectopic pregnancy can present as abdominal pain, and missing it is catastrophic.
Then perform: Focused physical exam — abdominal, and pelvic exam if female with lower abdominal pain.
Stat labs:
• CBC (WBC for infection/inflammation, Hgb for bleeding)
• BMP (electrolytes, renal function)
• LFTs (hepatic panel: AST, ALT, bilirubin, alkaline phosphatase)
• Lipase (pancreatitis)
• Urinalysis (UTI, kidney stone)
• Urine pregnancy test (all women of childbearing age)
• Lactate (if concern for bowel ischemia or sepsis)
• Blood type and screen (if surgical intervention likely)
Initial imaging decision depends on location:
Workup by Quadrant
Right Upper Quadrant (RUQ) Pain
Think: Cholecystitis, choledocholithiasis, hepatitis, liver abscess, right-sided pneumonia
Imaging sequence:
1. RUQ ultrasound (first-line for biliary disease)
2. If ultrasound shows gallstones + wall thickening + Murphy's sign → cholecystitis
3. HIDA scan if ultrasound is equivocal
4. MRCP or ERCP if concern for common bile duct stone
Management for cholecystitis:
• IV antibiotics (piperacillin-tazobactam or ceftriaxone + metronidazole)
• Surgical consult for cholecystectomy
• NPO, IV fluids
• Pain management
Left Upper Quadrant (LUQ) Pain
Think: Splenic pathology, pancreatitis, gastritis, left-sided pneumonia
Key tests: Lipase (pancreatitis), CT abdomen if splenic concern
Right Lower Quadrant (RLQ) Pain
Think: Appendicitis, ovarian pathology (torsion, cyst rupture, ectopic), Crohn's disease, mesenteric lymphadenitis
Imaging sequence:
1. CT abdomen/pelvis with contrast (first-line for suspected appendicitis in adults)
2. Pelvic ultrasound if female and gynecologic cause suspected
3. Transvaginal ultrasound if ectopic pregnancy suspected
Management for appendicitis:
• Surgical consult for appendectomy
• IV antibiotics (cefoxitin or piperacillin-tazobactam)
• NPO, IV fluids
Left Lower Quadrant (LLQ) Pain
Think: Diverticulitis, sigmoid volvulus, ovarian pathology, colon cancer
Key tests: CT abdomen/pelvis with contrast, CBC, UA
Management for diverticulitis:
• Uncomplicated: antibiotics (ciprofloxacin + metronidazole or amoxicillin-clavulanate), bowel rest, clear liquids
• Complicated (abscess, perforation, obstruction): surgical consult, NPO, IV antibiotics, percutaneous drainage of abscess if applicable
Epigastric Pain
Think: Pancreatitis, PUD/gastritis, MI (especially inferior), GERD, AAA
Pancreatitis workup and management:
• Lipase (3x upper limit of normal = diagnostic)
• CT abdomen (if unclear diagnosis or to assess severity)
• Management: aggressive IV fluid resuscitation, NPO, pain control, monitor for complications
• Ranson's criteria or BISAP score for severity
• No antibiotics unless infected necrosis suspected
PUD/Gastritis:
• H. pylori testing (urea breath test or stool antigen)
• PPI (omeprazole or pantoprazole)
• EGD if alarm symptoms (weight loss, anemia, dysphagia) or failure to respond
Diffuse / Periumbilical Pain
Think: Small bowel obstruction, mesenteric ischemia, early appendicitis, gastroenteritis, AAA
Small bowel obstruction:
• Abdominal X-ray (air-fluid levels, dilated loops)
• CT abdomen if diagnosis unclear
• NG tube decompression
• NPO, IV fluids
• Surgical consult (especially if concern for strangulation)
• Monitor for signs of bowel compromise: increasing pain, fever, leukocytosis, peritoneal signs
Mesenteric ischemia:
• CT angiography of abdomen
• Lactate (elevated = concerning)
• Surgical consult — emergent
• Anticoagulation
• This is a don't-miss diagnosis
Surgical vs. Medical: When to Call Surgery
Call a surgical consult for:
• Appendicitis
• Cholecystitis
• Bowel obstruction (especially with signs of strangulation)
• Perforated viscus (free air on imaging)
• Mesenteric ischemia
• Ruptured ectopic pregnancy
• Ruptured AAA
• Diverticulitis with abscess or perforation
Do NOT call surgery for:
• Uncomplicated pancreatitis
• Uncomplicated diverticulitis
• GERD/PUD (unless perforation)
• Gastroenteritis
• Kidney stones (call urology if obstructive or large)
Don't-Miss Diagnoses for Abdominal Pain
1. Ectopic pregnancy — Any woman of childbearing age with lower abdominal pain. Always get a pregnancy test.
2. Ruptured AAA — Older man with sudden abdominal/back pain + hypotension = emergent surgery. Do NOT delay with imaging if hemodynamically unstable.
3. Mesenteric ischemia — "Pain out of proportion to exam" in a patient with atrial fibrillation or vascular disease. High mortality if missed.
4. Perforated viscus — Rigid abdomen, free air on imaging = surgical emergency.
5. Ovarian torsion — Sudden onset lower abdominal pain in a young woman, often with nausea/vomiting. Needs emergent pelvic ultrasound and surgical consult.
6. Strangulated hernia — Irreducible hernia with pain, vomiting → surgical emergency.
The Complete Order Set: Abdominal Pain (ER)
Immediate:
• IV access, NPO
• Vital signs, cardiac monitor (if unstable)
• Pain management (morphine IV or ketorolac IV)
• Urine pregnancy test (all women of childbearing age)
Labs:
• CBC, BMP, LFTs, lipase
• Urinalysis
• Lactate (if concern for ischemia or sepsis)
• Blood type and screen
• Coagulation studies (if surgical intervention likely)
• Blood cultures (if febrile)
Imaging (choose based on location):
• Abdominal X-ray (obstruction, free air)
• RUQ ultrasound (biliary disease)
• CT abdomen/pelvis with contrast (most common advanced imaging)
• Pelvic/transvaginal ultrasound (gynecologic causes)
• CT angiography (mesenteric ischemia, AAA)
Treatment (condition-specific):
• Antibiotics for infectious causes (cultures first if applicable)
• Surgical consult for surgical abdomen
• NPO + NG tube for obstruction
• Aggressive IV fluids for pancreatitis
• PPI for PUD/GERD
Disposition:
• ICU for hemodynamically unstable patients, post-op critical care
• Floor for stable surgical and medical patients
• Discharge for uncomplicated conditions with outpatient follow-up
• Follow-up appointment in 1–2 weeks
• Diet counseling as appropriate
• Preventive care on 2-minute screen
Related Chief Complaint Articles:
• CCS Chest Pain: Orders, Algorithms & Don't-Miss Diagnoses
• CCS Shortness of Breath: Complete Approach & Order Sets
• CCS Altered Mental Status: First 60 Seconds to Disposition
• CCS Fever & Sepsis: Rapid Workup, Orders & Escalation
• Ultimate Guide to CCS Section of Step 3 (2026)