Diagnostic Imaging Pathways - Iliac Fossa Pain (Acute Left)

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Population Covered By The Guidance

This pathway provides guidance on the imaging of adult patients with left iliac fossa pain, with emphasis on investigations for suspected diverticulitis and its complications.

Date reviewed: October 2018

Date of next review: October 2021

Published: April 2019

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No radiation None 0
Minimal radiation Minimal < 1 millisieverts
Low radiation Low 1-5 mSv
Medium radiation Medium 5-10 mSv
High radiation High >10 mSv


Pathway Diagram


Image Gallery

Note: These images open in a new page
1a Click to view full size image


Image 1a (Computed Tomography): Inflammatory changes are seen around the sigmoid colon without abscess formation (arrow).

1b Click to view full size image Image 1b (Computed Tomography): Sigmoid diverticulitis complicated by an abscess (arrow).
2a Click to view full size image Diverticular Disease

Image 2a: Sigmoid colectomy showing multiple diverticular outpouchings through the bowel wall. Note the attenuated muscularis propria (black arrows) compared to the normal muscle layer (blue arrow).

2b Click to view full size image Image 2b (H&E, x2.5): Histological section showing an uninflamed diverticulum extending through the muscularis propria of the large bowel wall.

{tab=Teaching Points}

Teaching Points


Transabdominal/Transvaginal Ultrasound


Computed Tomography (CT)


Plain Radiography


Ultrasound in Diverticulitis


Management of Acute Diverticulitis



References are graded from Level I to V according to the Oxford Centre for Evidence-Based Medicine, Levels of Evidence. Download the document

  1. Bhosale PR, Javitt MC, Atri M, Harris RD, Kang SK, Meyer BJ, et al. ACR Appropriateness criteria(R) acute pelvic pain in the reproductive age group. Ultrasound quarterly. 2016;32(2):108-15. (Guideline). View the reference
  2. Bhavsar AK, Gelner EJ, Shorma T. Common Questions About the Evaluation of Acute Pelvic Pain. Am Fam Physician. 2016;93(1):41-8. (Review article). View the reference
  3. Katz DS, Khalid M, Coronel EE, Mazzie JP. Computed tomography imaging of the acute pelvis in females. Can Assoc Radiol J. 2013;64(2):108-18. (Review article). View the reference
  4. Ackerman SJ, Irshad A, Anis M. Ultrasound for pelvic pain II: nongynecologic causes. Obstet Gynecol Clin North Am. 2011;38(1):69-83, viii. (Review article). View the reference
  5. Amirbekian S, Hooley RJ. Ultrasound evaluation of pelvic pain. Radiol Clin North Am. 2014;52(6):1215-35. (Review article). View the reference
  6. O'Malley ME, Wilson SR. Ultrasonography and computed tomography of appendicitis and diverticulitis. Semin Roentgenol. 2001;36(2):138-47. (Review article). View the reference
  7. American College of Radiology. ACR appropriateness criteria. Left lower quadrant pain - suspected diverticulitis. 2014. (Guideline). View the reference
  8. Sartelli M, Catena F, Ansaloni L, Coccolini F, Griffiths EA, Abu-Zidan FM, et al. WSES Guidelines for the management of acute left sided colonic diverticulitis in the emergency setting. World J Emerg Surg. 2016;11(1):37. (Guideline). View the reference
  9. Binda GA, Cuomo R, Laghi A, Nascimbeni R, Serventi A, Bellini D, et al. Practice parameters for the treatment of colonic diverticular disease: Italian Society of Colon and Rectal Surgery (SICCR) guidelines. Techniques in coloproctology. 2015;19(10):615-26. (Guidelines). View the reference
  10. Andeweg CS, Mulder IM, Felt-Bersma RJ, Verbon A, van der Wilt GJ, van Goor H, et al. Guidelines of diagnostics and treatment of acute left-sided colonic diverticulitis. Dig Surg. 2013;30(4-6):278-92.
  11. Siddiqui J, Zahid A, Hong J, Young CJ. Colorectal surgeon consensus with diverticulitis clinical practice guidelines. World Journal of Gastrointestinal Surgery. 2017;9(11):224-32. View the reference
  12. Vennix S, Morton DG, Hahnloser D, Lange JF, Bemelman WA. Systematic review of evidence and consensus on diverticulitis: an analysis of national and international guidelines. Colorectal Dis. 2014;16(11):866-78. View the reference
  13. Galetin T, Galetin A, Vestweber KH, Rink AD. Systematic review and comparison of national and international guidelines on diverticular disease. Int J Colorectal Dis. 2018;33(3):261-72.(Review article) View the reference
  14. Lameris W, van Randen A, van Gulik TM, Busch OR, Winkelhagen J, Bossuyt PM, et al. A clinical decision rule to establish the diagnosis of acute diverticulitis at the emergency department. Dis Colon Rectum. 2010;53(6):896-904. (Level II-III evidence). View the reference
  15. Toorenvliet BR, Bakker RF, Breslau PJ, Merkus JW, Hamming JF. Colonic diverticulitis: a prospective analysis of diagnostic accuracy and clinical decision-making. Colorectal Dis. 2010;12(3):179-86. (Level II-III evidence). View the reference
  16. Andeweg CS, Knobben L, Hendriks JC, Bleichrodt RP, van Goor H. How to diagnose acute left-sided colonic diverticulitis: proposal for a clinical scoring system. nn Surg. 2011;253(5):940-6. (Level II-III evidence). View the reference
  17. Andeweg CS, Wegdam JA, Groenewoud J, van der Wilt GJ, van Goor H, Bleichrodt RP. Toward an evidence-based step-up approach in diagnosing diverticulitis. Scand J Gastroenterol. 2014;49(7):775-84. (Level I evidence). View the reference
  18. Barat M, Dohan A, Pautrat K, Boudiaf M, Dautry R, Guerrache Y, et al. Acute colonic diverticulitis: an update on clinical classification and management with MDCT correlation. Abdominal radiology (New York). 2016;41(9):1842-50. (Review article). View the reference
  19. Shin S, Kim D, Kang UR, Yang C-S. Impact of CT imaging on predicting the surgical management of acute diverticulitis. Annals of Surgical Treatment and Research. 2018;94(6):322-9. (Level II-III evidence). View the reference
  20. Sharma PV, Eglinton T, Hider P, Frizelle F. Systematic review and meta-analysis of the role of routine colonic evaluation after radiologically confirmed acute diverticulitis. Ann Surg. 2014;259(2):263-72. (Level I evidence). View the reference
  21. Andrade P, Ribeiro A, Ramalho R, Lopes S, Macedo G. Routine colonoscopy after acute uncomplicated diverticulitis - challenging a putative indication. Dig Surg. 2017;34(3):197-202. (Level II-III evidence). View the reference
  22. Daniels L, Unlu C, de Wijkerslooth TR, Stockmann HB, Kuipers EJ, Boermeester MA, et al. Yield of colonoscopy after recent CT-proven uncomplicated acute diverticulitis: a comparative cohort study. Surg Endosc. 2015;29(9):2605-13. (Level III evidence). View the reference
  23. Campbell JP, Gunn AA. Plain abdominal radiographs and acute abdominal pain. Br J Surg. 1988;75(6):554-6. (Level III evidence). View the reference
  24. Li Y, Song J, Lin N, Zhao C. Computed tomography scan is superior to x-ray plain film in the diagnosis of gastrointestinal tract perforation. Am J Emerg Med. 2015;33(3):480.e3-5. (Review article). View the reference
  25. Min JH, Kim HC, Kim SW, Yang DM, Rhee SJ, Oh J, et al. The value of initial sonography compared to supplementary CT for diagnosing right-sided colonic diverticulitis. Japanese journal of radiology. 2017;35(7):358-65. (Level II-III evidence). View the reference
  26. Laméris W, van Randen A, van Es HW, van Heesewijk JPM, van Ramshorst B, Bouma WH, et al. Imaging strategies for detection of urgent conditions in patients with acute abdominal pain: diagnostic accuracy study. BMJ. 2009;338 (Level II-III evidence). View the reference
  27. Puylaert JB. Ultrasound of colon diverticulitis. Dig Dis. 2012;30(1):56-9. (Level III-IV evidence). View the reference
  28. Feingold D, Steele SR, Lee S, Kaiser A, Boushey R, Buie WD, et al. Practice parameters for the treatment of sigmoid diverticulitis. Dis Colon Rectum. 2014;57(3):284-94. (Guideline) View the reference
  29. Stollman N, Smalley W, Hirano I. American Gastroenterological Association institute guideline on the management of acute diverticulitis. Gastroenterology. 2015;149(7):1944-9. (Guideline) View the reference
  30. Chabok A, Pahlman L, Hjern F, Haapaniemi S, Smedh K. Randomized clinical trial of antibiotics in acute uncomplicated diverticulitis. Br J Surg. 2012;99(4):532-9. (Level II evidence) View the reference
  31. Shabanzadeh DM, Wille-Jorgensen P. Antibiotics for uncomplicated diverticulitis. Cochrane Database Syst Rev. 2012;11:Cd009092. (Level I evidence) View the reference
  32. Nally DM, Kavanagh DO. Current controversies in the management of diverticulitis: a review. Dig Surg. 2018. (Review article) View the reference
  33. Sharma PV, Eglinton T, Hider P, Frizelle F. Systematic review and meta-analysis of the role of routine colonic evaluation after radiologically confirmed acute diverticulitis. Ann Surg. 2014;259(2):263-72. (Level I evidence) View the reference
  34. Chabok A, Smedh K, Nilsson S, Stenson M, Pahlman L. CT-colonography in the follow-up of acute diverticulitis: patient acceptance and diagnostic accuracy. Scand J Gastroenterol. 2013;48(8):979-86. (Level II-III evidence) View the reference
  35. Laghi A. CT Colonography: an update on current and future indications. Expert review of gastroenterology & hepatology. 2016;10(7):785-94. (Review article) View the reference

{tab=Information for Consumers}

Information for Consumers

Information from this website

Information from the Royal Australian and New Zealand College of Radiologists’ website

Radiation Risks of X-rays and Scans

Computed Tomography (CT)


Plain Radiography (X-ray)

Computed Tomography (CT)

Iodine-Containing Contrast Medium

Plain Radiography/X-rays

Radiation Risk of Medical Imaging During Pregnancy

Radiation Risk of Medical Imaging for Adults and Children




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