Renal colic mimics


  • Some mimics of renal colic that may arrive at the ED include: upper UTI’s, ectopic pregnancies, ovarian torsion, adnexal masses, testicular torsion, acute aortic syndromes, renal artery aneurysms, renal infarction, splenic infarction, bowel obstruction, diverticulitis, appendicitis, biliary colic, cholecystitis, acute intestinal ischemia, pneumonia, pulmonary embolism, retroperitoneal hematoma, iliopsoas abscess.
  • Focused history and physical exam are paramount due to the multitude of structures in the area and potentially dangerous conditions that may mimic renal colic.
  • Flank pain and hematuria are the hallmarks of renal colic, however, the presentation is variable.
  • Diagnosis can be confirmed with CT scan, which will show most other potential items in the differential if the scan is negative for a stone.


The Pregnant Peritonitis


  • The gravid uterus can mask the signs of peritoneal irritation (guarding, rigidity and rebound tenderness) by preventing the inflamed organ from contacting the peritoneum.
  • Due to increased white blood cells that naturally occur during pregnancy, leukocytosis is not helpful in identifying acute pathology.
  • A relative increase in blood volume can delay the development of tachycardia and hypotension in the truly ill patient.
  • Consider appendicitis in the patient complaining of typical signs and symptoms of appendicitis even if confounded by right middle and upper quadrant abdominal pain, pyuria, urinary symptoms and subtle signs of peritonitis.
  • HELLP syndrome is managed with blood pressure control, prevention of seizures, correction of coagulopathy, and delivery of the fetus.
  • Radiological investigations, including abdominal plain films, can be safely undertaken during pregnancy and should always be considered so as to avoid delays and failures in diagnosing potentially life-threatening conditions.





There is no individual sign or symptom that can reliably exclude appendicitis in any patient. (Vissers RJ, 2010) The three most valuable historical clues include RLQ pain, migration of pain from the periumbilical region to the RLQ, and pain occurring prior to vomiting.  Symptoms helpful in excluding appendicitis include previous histories of similar pain and the absence of RLQ pain. (Cole MA, 2011)

There are three commonly used scoring systems to evaluate for appendicitis. These can be helpful to risk stratify patients who have signs and symptoms concerning for appendicitis. These three scores include the Alvarado Score (AS), the Pediatric Appendicitis Score (PAS), and the Appendicitis Inflammatory Response Score (AIRS). While the Appendicitis Inflammatory Response Score has demonstrated better performance than the Alvarado Score, all scoring systems are, alone, inadequate for determining the need for surgical intervention. They are however, good for risk stratifying the need for imaging studies.  (Andersson M, 2008)

Why on earth does radiology insist on oral contrast?

Small Bowel Obstruction – Oral contrast is contraindicated in suspected in SBO. IV contrast is preferred, but not required.

Suspected appendicitis – Oral contrast is not required, but may be beneficial in extremely thin individuals (e.g. BMI < 18), or non-obese children.

Suspected diverticulitis – Oral contrast is not required

Unclear etiology – PO contrast is suggested by some experts in undifferentiated abd pain if the patient is very thin (e.g. < 120 pounds, BMI < 18); has had a Roux-en-Y gastric bypass; or has and inflammatory bowel disease that could produce a fistula