Stethopedia | Approach

Approach to

Abdominal Pain

Act first on shock, peritonitis, pain out of proportion and possible ruptured ectopic; then localize the pain and let lipase, liver tests and site-directed imaging (CT for most, ultrasound for RUQ or pelvic pain) find the cause.

  1. Acute abdominal pain in an adult
  2. β-hCG if could be pregnant; vitals; abdominal, pelvic or genital and rectal exam2
  3. CBC, lytes, creatinine, LFTs, lipase, lactate, UA; ECG if upper pain2
  4. Red flags of an acute abdomen?

Acute abdomen: resuscitate, call surgery/gyne1,2

  • Hypotension, tachycardia or sepsis
  • Rigidity, guarding or rebound
  • Pain out of proportion to the exam11
  • Bilious vomiting, obstipation12
  • Hematemesis or hematochezia
  • β-hCG + with shock or peritonism8

→ Sepsis: fluids, antibiotics; AAA: permissive hypotension, OR10

If not: where is the pain?

CausesCluesWorkupManagement

Upper abdomen

  • Acute cholangitis
  • Biliary colic, cholecystitis
  • Pancreatitis, peptic ulcer
  • Fever, jaundice; full triad often absent5
  • Murphy sign weak: LR 2.8 (CI 0.8–8.6)6
  • Epigastric pain boring to the back
  • RUQ US first; MRCP if CBD stone possible4
  • Lipase >3× ULN + typical pain7
  • CT only if pancreatitis unclear7
  • Cholangitis: antibiotics, ERCP2
  • Cholecystitis: early cholecystectomy2
  • Pancreatitis: moderate fluids, early PO7

Lower abdomen, pelvis

  • Ectopic pregnancy
  • Ovarian or testicular torsion
  • Appendicitis, diverticulitis, stone, PID
  • Pain migrating to RLQ; fever
  • Vaginal bleeding; missed period8
  • Sudden one-sided pain with vomiting
  • β-hCG +: transvaginal ultrasound8
  • CT with IV contrast; noncontrast if stone1,2
  • Doppler US if torsion; US first if pregnant9
  • No IUP: PUL; serial β-hCG, gynecology8
  • Torsion: urgent surgical detorsion
  • Surgery; antibiotics if uncomplicated9

Diffuse

  • Ruptured AAA or aortic dissection
  • Mesenteric ischemia
  • Perforation, obstruction, volvulus
  • Older smoker; back pain, pulsatile mass10
  • Pain out of proportion; AF11
  • Colicky pain, prior surgery or hernia12
  • CTA if ischemia or aortic cause10,11
  • Bedside ultrasound for AAA if unstable
  • CT with IV contrast, not plain films1,12
  • Rupture: door-to-repair <90 min10
  • Ischemia: heparin, revascularize11
  • SBO: NG tube, fluids; OR if strangulated12

Image-negative

  • Inferior MI
  • DKA, adrenal crisis
  • Hypercalcemia, pneumonia, zoster, IBS
  • Cardiac risk with upper abdominal pain
  • Carnett sign: abdominal wall pain2
  • Normal imaging; recurrent pain
  • ECG ± troponin2
  • Glucose, calcium, gas, cortisol
  • CXR if cough or hypoxemia
  • Treat cause: ACS, DKA, hypercalcemia
  • Adrenal crisis: IV hydrocortisone 100 mg2
  • Functional: TCA or SNRI, not opioids2

Can't-miss cause Superscripts link to the references below.

References

  1. Expert Panel on Gastrointestinal Imaging; Scheirey CD, Fowler KJ, et al. ACR Appropriateness Criteria acute nonlocalized abdominal pain. J Am Coll Radiol. 2018;15:S217–S231. PubMed 30392591
  2. Gay E, Levy N, eds. Abdominal Pain; Pancreatitis and Pancreatic Mass; Biliary Disease; Adrenal Disorders. In: Department of Medicine Housestaff Manual, 30th ed. 2024:69, 82, 85, 182.
  3. Ohle R, O'Reilly F, O'Brien KK, et al. The Alvarado score for predicting acute appendicitis: a systematic review. BMC Med. 2011;9:139. PubMed 22204638
  4. Expert Panel on Gastrointestinal Imaging; Russo GK, Zaheer A, et al. ACR Appropriateness Criteria right upper quadrant pain: 2022 update. J Am Coll Radiol. 2023;20:S211–S223. PubMed 37236744
  5. Kiriyama S, Kozaka K, Takada T, et al. Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholangitis. J Hepatobiliary Pancreat Sci. 2018;25:17–30. PubMed 29032610
  6. Trowbridge RL, Rutkowski NK, Shojania KG. Does this patient have acute cholecystitis? JAMA. 2003;289:80–86. PubMed 12503981
  7. Tenner S, Vege SS, Sheth SG, et al. American College of Gastroenterology guidelines: management of acute pancreatitis. Am J Gastroenterol. 2024;119:419–437. PubMed 38857482
  8. Po L, Thomas J, Mills K, et al. Guideline No. 414: management of pregnancy of unknown location and tubal and nontubal ectopic pregnancies. J Obstet Gynaecol Can. 2021;43:614–630.e1. PubMed 33453378
  9. Di Saverio S, Podda M, De Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020;15:27. PubMed 32295644
  10. Chaikof EL, Dalman RL, Eskandari MK, et al. The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm. J Vasc Surg. 2018;67:2–77. PubMed 29268916
  11. Bala M, Catena F, Kashuk J, et al. Acute mesenteric ischemia: updated guidelines of the World Society of Emergency Surgery. World J Emerg Surg. 2022;17:54. PubMed 36261857
  12. Ten Broek RPG, Krielen P, Di Saverio S, et al. Bologna guidelines for diagnosis and management of adhesive small bowel obstruction (ASBO): 2017 update. World J Emerg Surg. 2018;13:24. PubMed 29946347

For education only; not a substitute for clinical judgment or local protocols. Where sources differ, the flowchart follows the current guideline.

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