Evaluation and Management of Right Lower Quadrant Pain with Gross Hematuria
Obtain a contrast-enhanced CT scan of the abdomen and pelvis immediately, as this is the single most appropriate imaging study to evaluate both urolithiasis (the most likely diagnosis given gross hematuria) and alternative intra-abdominal pathologies including appendicitis, with sensitivity >95% for detecting both conditions. 1
Initial Diagnostic Imaging
The American College of Radiology rates contrast-enhanced CT abdomen/pelvis as "usually appropriate" (7-9/9) for evaluating right lower quadrant pain when the diagnosis is unclear, and this modality provides comprehensive evaluation of both renal/ureteral pathology and intra-abdominal causes with high diagnostic accuracy 1
CT demonstrates sensitivity of 85.7-100% and specificity of 94.8-100% for appendicitis, while simultaneously detecting urolithiasis, diverticulitis, bowel obstruction, mesenteric ischemia, and other critical pathologies 2
The combination of RLQ pain with gross hematuria strongly suggests urolithiasis with referred pain, but appendicitis, right colonic diverticulitis, or inflammatory bowel disease remain important differential diagnoses that CT can definitively identify 1
Alternative Imaging Considerations
Ultrasound achieves 96% sensitivity when combining pyeloureteral dilation, direct stone visualization, and absence of ureteral ejaculation, making it an acceptable alternative in young patients or those with radiation concerns, though it provides limited evaluation of non-urologic RLQ pathology 1, 3
MRI is preferred over CT in pregnant patients with inconclusive ultrasound and can evaluate both renal parenchyma and intra-abdominal pathology without radiation exposure 1
Non-contrast CT reduces diagnostic accuracy and should be reserved only for patients with eGFR <30 mL/min/1.73m² or dialysis-dependent status, as IV iodinated contrast is generally safe in most CKD patients and should not be withheld when diagnostic benefit outweighs risk 1
Critical Management Principles
Do not delay CT beyond 12 hours if serious pathology is suspected, as conditions like mesenteric ischemia, perforated appendicitis, or renal infarction require urgent intervention 1
Gross hematuria following blunt trauma has 77% likelihood of significant urologic injury requiring intervention, but in non-trauma settings with RLQ pain, the hematuria more likely indicates urolithiasis with ureteral obstruction 4
The radiologist must specifically evaluate the appendix, right colon, kidneys, ureters, and mesentery/vessels for appendicitis, diverticulitis, urolithiasis, or renal infarction 1
Common Diagnostic Pitfalls
Do not assume hematuria alone indicates the pain is purely renal, as hematuria may be incidental or chronic while the acute RLQ pain could be from appendicitis or other intra-abdominal pathology 1
Do not rely on non-contrast CT alone, as critical findings like bowel wall enhancement, abscess formation, and vascular complications cannot be detected without IV contrast 1
Although appendicitis accounts for nearly 50% of RLQ pain presentations, numerous other bowel, mesenteric, vascular, urinary, and reproductive conditions can simulate this presentation and require imaging for definitive diagnosis 5, 6
Specific Imaging Findings to Guide Management
If CT demonstrates urolithiasis with hydronephrosis, management depends on stone size, degree of obstruction, and presence of infection requiring urgent urologic consultation 7
If CT shows appendicitis, proceed directly to appendectomy, as preoperative CT reduces negative appendectomy rates from 16.7% to 8.7% 2
If CT identifies right colonic diverticulitis, appendicitis, or intestinal obstruction as alternative diagnoses, direct treatment at the specific pathology identified 5, 3