Structures abdominal pain workups with differential by quadrant and surgical consultation criteria. Use when assessing acute abdomen, determining imaging needs, or identifying surgical emergencies.
Structures abdominal pain workups with differential diagnosis by quadrant location, laboratory and imaging selection, and surgical consultation criteria for acute abdomen.
Abdominal pain is the most common chief complaint in US emergency departments, accounting for approximately 8% of all ED visits (11 million annually). The differential diagnosis spans over 50 conditions across multiple organ systems, and the diagnostic challenge is compounded by the fact that history and physical exam alone have limited sensitivity for surgical conditions — clinical accuracy for appendicitis, for example, ranges from 70-87% without imaging. Missed surgical emergencies (ruptured AAA, mesenteric ischemia, perforated viscus) carry mortality rates of 40-80% if treatment is delayed.
Overtesting is equally problematic: CT abdomen/pelvis exposes patients to 10 mSv of radiation (equivalent to ~500 chest X-rays), and contrast-induced nephropathy affects 1-6% of patients with renal insufficiency. This skill provides a systematic framework for efficient, accurate abdominal pain evaluation that avoids both undertesting and overtesting.
| Diagnosis | Key Features | Workup |
|---|---|---|
| Acute cholecystitis | RUQ pain, positive Murphy sign, fever | RUQ ultrasound (sensitivity 88%, specificity 80%); CBC, hepatic panel |
| Choledocholithiasis | RUQ pain, jaundice, elevated bilirubin/ALP | MRCP or EUS if ultrasound equivocal; GI consult for ERCP |
| Ascending cholangitis (Charcot triad) | RUQ pain + fever + jaundice | Blood cultures, emergent ERCP; add hypotension + AMS = Reynolds pentad |
| Hepatitis | RUQ pain, elevated transaminases (>1000 suggests viral/toxin) | Hepatic panel, hepatitis serologies, toxicology |
| Hepatic abscess | Fever, RUQ pain, recent travel or biliary disease | CT with contrast, blood cultures |
| Diagnosis | Key Features | Workup |
|---|---|---|
| Appendicitis | Periumbilical pain migrating to RLQ, anorexia, low-grade fever | CT abdomen/pelvis (sensitivity 98%); Alvarado score ≥7 highly suggestive |
| Ovarian torsion | Sudden severe unilateral pelvic pain, nausea | Pelvic ultrasound with Doppler (sensitivity 85-90%); gynecology consult |
| Ectopic pregnancy | Missed period, vaginal bleeding, pelvic pain, positive hCG | Transvaginal ultrasound; quantitative hCG; if ruptured → emergent OR |
| Mesenteric adenitis | RLQ pain in young patient, often viral prodrome | CT may mimic appendicitis; clinical observation |
| Diagnosis | Key Features | Workup |
|---|---|---|
| Splenic infarct/rupture | LUQ pain, history of hematologic disorder, trauma | CT with IV contrast |
| Gastric ulcer perforation | Sudden epigastric/LUQ pain, peritonitis | Upright CXR (free air), CT if CXR negative |
| Pancreatitis | Epigastric/LUQ pain radiating to back, nausea, vomiting | Lipase (>3× upper limit), CT for complications if no improvement at 48-72h |
| Diagnosis | Key Features | Workup |
|---|---|---|
| Diverticulitis | LLQ pain, fever, leukocytosis; common in age >50 | CT abdomen/pelvis with IV contrast (sensitivity >95%) |
| Sigmoid volvulus | Elderly, institutionalized, chronic constipation, distension | Abdominal X-ray (bent inner tube sign); CT confirms; rectal tube decompression |
| Ovarian pathology | Unilateral pelvic pain, menstrual irregularity | Pelvic ultrasound, beta-hCG |
| Diagnosis | Key Features | Workup |
|---|---|---|
| Small bowel obstruction | Colicky pain, vomiting, distension, prior surgery | CT abdomen/pelvis; look for transition point |
| Mesenteric ischemia | Severe pain out of proportion to exam, AFib, age >60 | CT angiography; lactate (late finding); vascular surgery consult |
| Ruptured AAA | Sudden severe pain, pulsatile mass, hypotension, age >60, male | Bedside ultrasound (if stable); emergent OR if unstable (do NOT delay for CT) |
| Peritonitis | Rigid abdomen, guarding, rebound, involuntary guarding | Surgical consult immediately; imaging secondary to clinical diagnosis |
| Clinical Scenario | First-Line Imaging | Notes |
|---|---|---|
| RUQ pain, suspected biliary | RUQ ultrasound | Do NOT order CT first for biliary disease |
| RLQ pain, suspected appendicitis | CT abdomen/pelvis with IV contrast | Ultrasound first in pediatric, pregnant, or young thin females |
| Suspected bowel obstruction | CT abdomen/pelvis with IV contrast | X-ray has poor sensitivity for partial SBO |
| Suspected renal colic | CT abdomen/pelvis without contrast | Low-dose CT protocol preferred; ultrasound first if pregnant |
| Suspected AAA | Bedside POCUS (if unstable → OR) | CT angio if stable and diagnosis uncertain |
| Female pelvic pain | Pelvic ultrasound (transvaginal) | Always obtain beta-hCG first |
| Suspected free air | Upright CXR → CT if CXR negative | CT is more sensitive than X-ray |