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Acute abdomen

Last updated: August 9, 2021

Summarytoggle arrow icon

Acute abdomen refers to severe abdominal pain lasting for ≤ 5 days. The underlying pathology may be intra-abdominal, thoracic, or systemic and may require urgent surgical intervention. The initial approach to acute abdomen should be to assess for immediately life-threatening causes (e.g., ruptured abdominal aortic aneurysm, bowel perforation) by checking vital signs, performing a quick physical examination, and immediately conducting the appropriate focused diagnostic tests (e.g., abdominal ultrasound, abdominal x-ray). Once emergency causes have been ruled out, a thorough history and physical examination should be performed to narrow the differential diagnoses and guide further diagnostic workup and therapy. Traumatic causes of abdominal pain, abdominal trauma, and chronic abdominal pain are not addressed here.

Approach to management [1]

Red flags for abdominal pain

Immediately life-threatening diagnoses

The diagnostic workup should be guided by the pretest probability of the diagnoses under consideration. The following list includes some commonly used diagnostic tools that can help to diagnose or rule out possible etiologies in a patient with acute abdominal pain.

Laboratory studies

A urine pregnancy test should be performed in every woman of reproductive age, regardless of current contraception use.
Patients with obvious signs of diffuse peritonitis do not require further diagnostic imaging and should proceed straight to surgical management.

Imaging [2][3][4][5][6][7][8]

Approach

  • The initial imaging modality should be guided by the working diagnosis, as based on the patient history, vital signs, and examination.
  • The following recommendations apply to nonpregnant adults.
  • In pregnant women with acute abdominal pain, ultrasound and/or MRI of the abdomen and/or pelvis without contrast are the preferred initial imaging modalities.

By suspected diagnosis [5]

Suspected diagnosis Recommended imaging modality
Acute coronary syndrome

Hemorrhagic shock [6]

Bowel perforation [2]
Small bowel obstruction [3]

Intra-abdominal abscess
  • CT abdomen and pelvis with IV contrast
Acute diverticulitis [7]
Acute appendicitis [4]

Acute mesenteric ischemia [9]
  • CTA of the abdomen
Acute pancreatitis [10]

Nephrolithiasis [11]
Acute complicated pyelonephritis [6]
  • CT abdomen and pelvis with IV contrast

Suspected symptomatic AAA in a hemodynamically stable patient [12]

By location of the pain

Site of pain
Initial test of choice

Alternatives

RUQ pain [13]

RLQ pain [4]

or

LLQ pain [7]
  • CT abdomen and pelvis with IV contrast

LUQ pain [14]
  • CT abdomen with oral and IV contrast

Suprapubic pain [14]

Pelvic pain [15]
  • Gynecological etiology suspected: Ultrasound pelvis (transabdominal and/or transvaginal)
  • Nongynecological etiology suspected and β-HCG is negative: CT abdomen and pelvis with IV contrast

Nonlocalized pain [2]
  • CT abdomen and pelvis with IV contrast
  • CT abdomen and pelvis without IV contrast
  • MRI abdomen and pelvis with/without IV contrast
  • Ultrasound abdomen and/or pelvis
  • Postoperative patients with acute abdomen: consider fluoroscopy (enema and/or upper abdominal series)

Consider diagnostic laparoscopy in hemodynamically stable patients in which the diagnosis is still unclear after complete physical examination and imaging. For patients with hemodynamic instability or severe abdominal distention, proceed to diagnostic laparotomy. [16]

In pregnant patients, regardless of the site of pain, ultrasound and MRI are the preferred initial imaging modalities.

Clinical features Diagnostic findings Acute management
Acute coronary syndrome [17][18]

Acute mesenteric ischemia

[19][20][21][22]
Rupture or impending rupture of AAA [23]

Aortic dissection

[24][25][26]
Clinical features Diagnostic findings Acute management
GI tract perforation [2][27][28]

Mechanical bowel obstruction [2][3][29][30]
  • X-ray abdomen
    • Dilated bowel loops proximal to the obstruction
    • Rectal air shadow absent
    • Multiple air-fluid levels
  • CT abdomen with IV and oral contrast
    • Similar findings as on x-ray
    • Transition point at site of obstruction

Acute appendicitis

[31][32][33][34]
Peptic ulcer disease [35][36][37]
Diverticulitis [38][39][40][41][42][43][44]
Clinical features Diagnostic findings Acute management

Acute pancreatitis

[45][46][47]
  • Severe epigastric pain that radiates to the back (circumferential pain)
  • Nausea, vomiting
  • Epigastric tenderness, guarding, rigidity
  • Hypoactive bowel sounds
  • Possibly fever
  • History of gallstones or alcohol use

Symptomatic cholelithiasis

[48][49][50]
Choledocholithiasis [48][51]

Acute cholecystitis

[48][49][54][55][56]

Acute cholangitis

[48][49][58][59] [54][60][61]
Clinical features Diagnostic findings Acute management
Ruptured ectopic pregnancy [62]
Ovarian torsion [63][64]
  • Sudden onset unilateral lower abdominal or pelvic pain
  • Nausea, vomiting
  • Unilateral iliac fossa tenderness
Testicular torsion [65]
Acute pyelonephritis [6][66][67][68][69]
Nephrolithiasis
  • Severe unilateral and colicky flank pain (renal colic)
  • Hematuria
  • Nausea, vomiting
  • Dysuria, frequency, and urgency

Approach

Community-acquired infections [70][71][72]

Severity of infection Suggested single-agent empiric regimen [70]

Suggested combination empiric regimen [70]

Mild or moderate infection
Severe infection
and/or
high-risk patient

Metronidazole is contraindicated in the first trimester of pregnancy.

Healthcare-associated infections [54][70][71][72]

Healthcare-associated infections are more likely to be antibiotic-resistant and both institutional and individual patient antibiograms should be considered when choosing an empiric regimen!

Patient and/or institutional risk factors
 Suggested empiric regimens [70]
Low risk (< 20%) of infection with resistant organism
High risk (> 20%) of infection with resistant organism
High risk of MRSA

  • Combination empiric regimen (see above)
  • PLUS vancomycin

Obtain cultures, if necessary, before the administration of empirical IV antibiotics.

For patients with a beta-lactam or carbapenem allergy, consider vancomycin with aztreonam and metronidazole.

Gastrointestinal etiologies [14] Nongastrointestinal etiologies [14]
RUQ
LUQ
RLQ
LLQ
Epigastrium
Periumbilical
Suprapubic
Diffuse abdominal pain

The differential diagnoses listed here are not exhaustive.

  1. Cartwright S, Knudson M. Evaluation of Acute Abdominal Pain in Adults. Am Fam Physician. 2008 .
  2. Macaluso C, McNamara. Evaluation and management of acute abdominal pain in the emergency department. International Journal of General Medicine. 2012 : p.789. doi: 10.2147/ijgm.s25936 . | Open in Read by QxMD
  3. Solomkin JS, Mazuski JE, Bradley JS, et al. Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis. 2010; 50 (2): p.133-164. doi: 10.1086/649554 . | Open in Read by QxMD
  4. American College of Radiology ACR Appropriateness Criteria® Acute Nonlocalized Abdominal Pain. https://acsearch.acr.org/docs/69467/Narrative/. Updated: January 1, 2018. Accessed: March 30, 2018.
  5. American College of Radiology ACR Appropriateness Criteria® Suspected Small-Bowel Obstruction. https://acsearch.acr.org/docs/69476/Narrative/. Updated: January 1, 2013. Accessed: June 3, 2019.
  6. American College of Radiology ACR Appropriateness Criteria® Right Lower Quadrant Pain-Suspected Appendicitis. https://acsearch.acr.org/docs/69357/Narrative/. Updated: January 1, 2018. Accessed: June 11, 2019.
  7. Cartwright SL, Knudson MP. Diagnostic Imaging of Acute Abdominal Pain in Adults. American Academy of Family Physicians. 2015; 91 (7): p.452-9.
  8. Mattson B, Dulaimy K. The 4 Quadrants: Acute Pathology in the Abdomen and Current Imaging Guidelines. Seminars in Ultrasound, CT and MRI. 2017; 38 (4): p.414-423. doi: 10.1053/j.sult.2017.02.006 . | Open in Read by QxMD
  9. American College of Radiology (ACR) Appropriateness Criteria® - Left Lower Quadrant Pain. https://acsearch.acr.org/docs/69356/Narrative/. Updated: January 1, 2018. Accessed: August 28, 2019.
  10. Paolantonio P, Rengo M, Ferrari R, Laghi A. Multidetector CT in emergency radiology: acute and generalized non-traumatic abdominal pain. Br J Radiol. 2016; 89 (1061): p.20150859. doi: 10.1259/bjr.20150859 . | Open in Read by QxMD
  11. American College of Radiology Appropriateness Criteria - Imaging of Mesenteric Ischemia. https://acsearch.acr.org/docs/70909/Narrative/. Updated: January 1, 2018. Accessed: October 29, 2019.
  12. American College of Radiology Appropriateness Criteria - Acute pancreatitis. https://acsearch.acr.org/docs/69468/Narrative/. Updated: January 1, 2019. Accessed: October 29, 2019.
  13. Moore CL, Carpenter CR, Heilbrun ME, et al. Imaging in Suspected Renal Colic: Systematic Review of the Literature and Multispecialty Consensus. Journal of the American College of Radiology. 2019 . doi: 10.1016/j.jacr.2019.04.004 . | Open in Read by QxMD
  14. Pulsatile Abdominal Mass, Suspected Abdominal Aortic Aneurysm. https://acsearch.acr.org/docs/69414/Narrative/. Updated: January 1, 2016. Accessed: January 10, 2020.
  15. American College of Radiology ACR Appropriateness Criteria® Right Upper Quadrant Pain. https://acsearch.acr.org/docs/69474/Narrative/. Updated: January 1, 2018. Accessed: August 28, 2019.
  16. Acute Pelvic Pain in the Reproductive Age Group. https://acsearch.acr.org/docs/69503/Narrative/. Updated: January 1, 2015. Accessed: August 28, 2019.
  17. Navez B, Navez J. Laparoscopy in the acute abdomen. Best Practice & Research Clinical Gastroenterology. 2014; 28 (1): p.3-17. doi: 10.1016/j.bpg.2013.11.006 . | Open in Read by QxMD
  18. Sartelli M. A focus on intra-abdominal infections. World Journal of Emergency Surgery. 2010; 5 (1): p.9. doi: 10.1186/1749-7922-5-9 . | Open in Read by QxMD
  19. Armstrong C. Practice Guidelines: Updated Guideline on Diagnosis and Treatment of Intra-abdominal Infections. Am Fam Physician. 2010 .
  20. Gomi H, Solomkin JS, Schlossberg D, et al. Tokyo Guidelines 2018: antimicrobial therapy for acute cholangitis and cholecystitis. Journal of Hepato-Biliary-Pancreatic Sciences. 2018; 25 (1): p.3-16. doi: 10.1002/jhbp.518 . | Open in Read by QxMD
  21. Lee C-T, Tu Y-K, Yeh Y-C, et al. Effects of polymyxin B hemoperfusion on hemodynamics and prognosis in septic shock patients. J Crit Care. 2018; 43 : p.202-206. doi: 10.1016/j.jcrc.2017.04.035 . | Open in Read by QxMD
  22. Bowel Perforation.
  23. Bowel perforation. https://radiopaedia.org/articles/bowel-perforation-1. . Accessed: November 25, 2019.
  24. Jackson PG, Raiji MT. Evaluation and Management of Intestinal Obstruction. American Family Physician. 2011; 83 (2): p.159-165.
  25. Griffiths S, Glancy DG. Intestinal obstruction. Surgery. undefined; 35 (3): p.3. doi: 10.1016/j.mpsur.2016.12.005 . | Open in Read by QxMD
  26. Di Saverio et al. WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis. World Journal of Emergency Surgery. 2016; 11 (1). doi: 10.1186/s13017-016-0090-5 . | Open in Read by QxMD
  27. Perez K, Allen S. Complicated appendicitis and considerations for interval appendectomy. Journal of the american academy of physician assistance. 2018; 31 .
  28. Snyder MJ, Guthrie M, Cagle S. Acute Appendicitis: Efficient Diagnosis and Management.. Am Fam Physician. 2018; 98 (1): p.25-33.
  29. Rushing A, Bugaev N, Jones C, et al. Management of acute appendicitis in adults. Journal of Trauma and Acute Care Surgery. 2019; 87 (1): p.214-224. doi: 10.1097/ta.0000000000002270 . | Open in Read by QxMD
  30. Kavitt RT, Lipowska AM, Anyane-Yeboa A, Gralnek IM. Diagnosis and Treatment of Peptic Ulcer Disease. Am J Med. 2019; 132 (4): p.447-456. doi: 10.1016/j.amjmed.2018.12.009 . | Open in Read by QxMD
  31. Satoh K, Yoshino J, Akamatsu T, et al. Evidence-based clinical practice guidelines for peptic ulcer disease 2015. J Gastroenterol. 2016; 51 (3): p.177-194. doi: 10.1007/s00535-016-1166-4 . | Open in Read by QxMD
  32. Fashner J, Gitu AC. Diagnosis and Treatment of Peptic Ulcer Disease and H. pylori Infection. Am Fam Physician.. 2015; 91 (4): p.236-242.
  33. Stollman N, Smalley W, Hirano I, et al. American Gastroenterological Association Institute Guideline on the Management of Acute Diverticulitis. Gastroenterology. 2015; 149 (7): p.1944-1949. doi: 10.1053/j.gastro.2015.10.003 . | Open in Read by QxMD
  34. Cuomo R, Cargiolli M, Cassarano S, Carabotti M, Annibale B. Treatment of diverticular disease, targeting symptoms or underlying mechanisms. Curr Opin Pharmacol. 2018; 43 : p.124-131. doi: 10.1016/j.coph.2018.09.006 . | Open in Read by QxMD
  35. Rezapour M, Stollman N. Antibiotics in Uncomplicated Acute Diverticulitis: To Give or Not to Give?. Inflammatory Intestinal Diseases. 2018; 3 (2): p.75-79. doi: 10.1159/000489631 . | Open in Read by QxMD
  36. Wilkins T, Embry K, George R. Diagnosis and Management of Acute Diverticulitis. American Family Physician. 2013; 87 (9): p.612-620.
  37. Tochigi T, Kosugi C, Shuto K, Mori M, Hirano A, Koda K. Management of complicated diverticulitis of the colon.. Annals of gastroenterological surgery. 2018; 2 (1): p.22-27. doi: 10.1002/ags3.12035 . | Open in Read by QxMD
  38. Siewert B, Tye G, Kruskal J, Sosna J, Opelka F. Impact of CT-Guided Drainage in the Treatment of Diverticular Abscesses: Size Matters. American Journal of Roentgenology. 2006; 186 (3): p.680-686. doi: 10.2214/ajr.04.1708 . | Open in Read by QxMD
  39. Wilkins T, Embry K, George R. Diagnosis and management of acute diverticulitis.. Am Fam Physician. 2013; 87 (9): p.612-20.
  40. Crockett et al. American Gastroenterological Association Institute Guideline on Initial Management of Acute Pancreatitis. Gastroenterology. 2018; 154 (4): p.1096-1101. doi: 10.1053/j.gastro.2018.01.032 . | Open in Read by QxMD
  41. D Jeffrey. Acute Pancreatitis. AAFP. 2014 .
  42. Vege SS, DiMagno MJ, Forsmark CE, Martel M, Barkun AN. Initial Medical Treatment of Acute Pancreatitis: American Gastroenterological Association Institute Technical Review. Gastroenterology. 2018; 154 (4): p.1103-1139. doi: 10.1053/j.gastro.2018.01.031 . | Open in Read by QxMD
  43. European Association for the Study of the Liver (EASL). EASL Clinical Practice Guidelines on the prevention, diagnosis and treatment of gallstones.. J Hepatol. 2016; 65 (1): p.146-181. doi: 10.1016/j.jhep.2016.03.005 . | Open in Read by QxMD
  44. Shirley A, Rivero H, et al. Surgical and Nonsurgical Management of Gallstones. Am Fam Physician. 2014 .
  45. Tazuma S, Unno M, Igarashi Y, et al. Evidence-based clinical practice guidelines for cholelithiasis 2016. J Gastroenterol. 2016; 52 (3): p.276-300. doi: 10.1007/s00535-016-1289-7 . | Open in Read by QxMD
  46. Maple JT, Ben-Menachem T, Anderson MA, et al. The role of endoscopy in the evaluation of suspected choledocholithiasis. Gastrointest Endosc. 2010; 71 (1): p.1-9. doi: 10.1016/j.gie.2009.09.041 . | Open in Read by QxMD
  47. Copelan A, Kapoor BS. Choledocholithiasis: Diagnosis and Management. Tech Vasc Interv Radiol. 2015; 18 (4): p.244-255. doi: 10.1053/j.tvir.2015.07.008 . | Open in Read by QxMD
  48. Choledocholithiasis. https://radiopaedia.org/articles/choledocholithiasis. Updated: January 1, 2019. Accessed: December 10, 2019.
  49. Yokoe M, Hata J, Takada T, et al. Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholecystitis (with videos). Journal of Hepato-Biliary-Pancreatic Sciences. 2018; 25 (1): p.41-54. doi: 10.1002/jhbp.515 . | Open in Read by QxMD
  50. Okamoto K, Suzuki K, Takada T, et al. Tokyo Guidelines 2018: flowchart for the management of acute cholecystitis. Journal of Hepatobiliary Pancreatic Sciences. 2017; 25 (1): p.55-72. doi: 10.1002/jhbp.516 . | Open in Read by QxMD
  51. Kiewiet JJS, Leeuwenburgh MMN, Bipat S, Bossuyt PMM, Stoker J, Boermeester MA. A Systematic Review and Meta-Analysis of Diagnostic Performance of Imaging in Acute Cholecystitis. Radiology. 2012; 264 (3): p.708-720. doi: 10.1148/radiol.12111561 . | Open in Read by QxMD
  52. Ahmed M. Acute cholangitis - an update. World J Gastrointest Pathophysiol. 2018; 9 (1): p.1-7. doi: 10.4291/wjgp.v9.i1.1 . | Open in Read by QxMD
  53. Miura F, Okamoto K, Takada T, et al. Tokyo Guidelines 2018: initial management of acute biliary infection and flowchart for acute cholangitis. Journal of Hepato-Biliary-Pancreatic Sciences. 2018; 25 (1): p.31-40. doi: 10.1002/jhbp.509 . | Open in Read by QxMD
  54. Mukai S, Itoi T, Baron TH, et al. Indications and techniques of biliary drainage for acute cholangitis in updated Tokyo Guidelines 2018.. Journal of hepato-biliary-pancreatic sciences. 2017; 24 (10): p.537-549. doi: 10.1002/jhbp.496 . | Open in Read by QxMD
  55. Kiriyama S, Kozaka K, Takada T, et al. Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholangitis (with videos). Journal of Hepato-Biliary-Pancreatic Sciences. 2018; 25 (1): p.17-30. doi: 10.1002/jhbp.512 . | Open in Read by QxMD
  56. O’Gara PT, Kushner FG, et al. 2013 ACCF/AHA Guideline for the Management of ST-Elevation Myocardial Infarction. Circulation. 2013; 127 (4). doi: 10.1161/cir.0b013e3182742cf6 . | Open in Read by QxMD
  57. E. A. Amsterdam, N. K. Wenger, R. G. Brindis, D. E. Casey Jr., T. G. Ganiats, D. R. Holmes Jr., A. S. Jaffe, H. Jneid, R. F. Kelly, M. C. Kontos, G. N. Levine, P. R. Liebson, D. Mukherjee, E. D. Peterson, M. S. Sabatine, R. W. Smalling, S. J. Zieman. 2014 AHA/ACC Guideline for the Management of Patients With Non–ST-Elevation Acute Coronary Syndromes. Journal of the American College of Cardiology. 2014 . doi: 10.1016/j.jacc.2014.09.017 . | Open in Read by QxMD
  58. Fidelman N, AbuRahma AF, Cash BD, et al. ACR Appropriateness Criteria ® Radiologic Management of Mesenteric Ischemia. Journal of the American College of Radiology. 2017; 14 (5): p.S266-S271. doi: 10.1016/j.jacr.2017.02.014 . | Open in Read by QxMD
  59. Brandt LJ, Boley SJ. AGA technical review on intestinal ischemia. Gastroenterology. 2000; 118 (5): p.954-968. doi: 10.1016/s0016-5085(00)70183-1 . | Open in Read by QxMD
  60. Bala M, Kashuk J, Moore EE, et al. Acute mesenteric ischemia: guidelines of the World Society of Emergency Surgery. World Journal of Emergency Surgery. 2017; 12 (1). doi: 10.1186/s13017-017-0150-5 . | Open in Read by QxMD
  61. Tilsed JVT, Casamassima A, Kurihara H, et al. ESTES guidelines: acute mesenteric ischaemia. European Journal of Trauma and Emergency Surgery. 2016; 42 (2): p.253-270. doi: 10.1007/s00068-016-0634-0 . | Open in Read by QxMD
  62. 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. Journal of Vascular Surgery. 2018; 67 (1): p.2-77.e2. doi: 10.1016/j.jvs.2017.10.044 . | Open in Read by QxMD
  63. Tsai TT, Nienaber CA, Eagle KA. Acute aortic syndromes.. Circulation. 2005; 112 (24): p.3802-13. doi: 10.1161/CIRCULATIONAHA.105.534198 . | Open in Read by QxMD
  64. Hiratzka LF, Bakris GL, Beckman JA, et al. 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease. Circulation. 2010; 121 (13): p.e266-369. doi: 10.1161/CIR.0b013e3181d4739e . | Open in Read by QxMD
  65. Marik PE, Rivera R. Hypertensive emergencies. Curr Opin Crit Care. 2011; 17 (6): p.569-580. doi: 10.1097/mcc.0b013e32834cd31d . | Open in Read by QxMD
  66. Barnhart K, Franasiak J, and the Committee on Practice Bulletins—Gynecology. ACOG Practice Bulletin No. 191: Tubal Ectopic Pregnancy. Obstetrics & Gynecology. 2018; 131 (2): p.e65-e77. doi: 10.1097/AOG.0000000000002464 . | Open in Read by QxMD
  67. R Eskander, M Berman, L Keder. Practice Bulletin No. 174. Obstetrics & Gynecology. 2016; 128 (5): p.e210-e226. doi: 10.1097/aog.0000000000001768 . | Open in Read by QxMD
  68. Ovarian torsion. https://radiopaedia.org/articles/ovarian-torsion. Updated: January 1, 2019. Accessed: January 10, 2020.
  69. Sharp VJ, Arlen AM. Testicular Torsion: Diagnosis, Evaluation, and Management. Am Fam Physician. 2013; 88 (12): p.835-840.
  70. Gupta K, Hooton TM, Naber KG, et al. Executive Summary: International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis. 2011; 52 (5): p.561-564. doi: 10.1093/cid/cir102 . | Open in Read by QxMD
  71. Colgan R, Williams M. Diagnosis and Treatment of Acute Pyelonephritis in Women. Am Fam Physician. 2011 .
  72. Ramakrishnan K, Scheid DC. Diagnosis and management of acute pyelonephritis in adults.. Am Fam Physician. 2005; 71 (5): p.933-942.
  73. Benson A. Renal Corticomedullary Abscess. In: Post TW, Renal Corticomedullary Abscess. New York, NY: WebMD. https://emedicine.medscape.com/article/440073-treatment. Updated: June 28, 2018. Accessed: September 30, 2018.
  74. O'Connell TX. USMLE Step 2 Secrets. Elsevier Saunders ; 2013
  75. Mavilia MG, Molina M,Wu GY. The Evolving Nature of Hepatic Abscess: A Review. J Clin Transl Hepatol. 2016; 4 (2). doi: 10.14218/jcth.2016.00004 . | Open in Read by QxMD