Right-Sided Abdominal Pain: Evaluation and Management
For right-sided abdominal pain, proceed directly to CT abdomen and pelvis with IV contrast as your first-line imaging study—this achieves 95% sensitivity and 94% specificity for appendicitis while simultaneously identifying alternative diagnoses in 23-45% of cases. 1
Immediate Pre-Imaging Actions
Before ordering imaging, complete these essential steps:
- Obtain beta-hCG testing in all women of reproductive age to exclude ectopic pregnancy and guide contrast decisions 1
- Establish NPO status and initiate IV fluid resuscitation to prepare for potential surgical intervention 1
- Obtain surgical consultation immediately if clinical suspicion for appendicitis is high, without waiting for imaging results 1
Location-Specific Imaging Strategy
The anatomic location of pain determines your imaging approach:
Right Upper Quadrant Pain
- Start with ultrasonography (rated 9/9 appropriateness by ACR) as the initial test for suspected biliary disease 2
- Ultrasonography is readily available, identifies multiple causes of pain, and avoids radiation exposure 2
- Follow with cholescintigraphy (rated 6/9) if ultrasound findings suggest acute cholecystitis, as it has superior sensitivity (96%) and specificity (90%) compared to ultrasound (81% and 83%) 2
- Reserve CT with IV contrast (rated 6/9) for inconclusive ultrasound results or surgical planning 2
Right Lower Quadrant Pain
- CT abdomen and pelvis with IV contrast is the definitive first-line imaging modality, explicitly recommended by the American College of Radiology over ultrasound 1
- CT provides superior diagnostic accuracy with 94% sensitivity and 76% specificity for appendicitis compared to ultrasound 2
- IV contrast is essential for optimal diagnostic performance; oral contrast is optional and may delay diagnosis without improving accuracy 1
- MRI without IV contrast achieves 97% sensitivity and 96% specificity for appendicitis and serves as an excellent radiation-free alternative, particularly in pregnant patients 2
Critical Differential Diagnoses by Location
Right Upper Quadrant
- Biliary pathology: Acute cholecystitis, choledocholithiasis, cholangitis 2
- Hepatic causes: Hepatitis, liver abscess, hepatic congestion 2
Right Lower Quadrant
- Gastrointestinal causes (60% of cases): Appendicitis, cecal diverticulitis, right-sided colonic diverticulitis, Crohn disease, bowel obstruction, colorectal malignancy 1
- Gynecologic causes in women: Ectopic pregnancy, ovarian torsion, tubo-ovarian abscess, ruptured ovarian cyst, pelvic inflammatory disease 1
- Urologic causes: Nephrolithiasis, pyelonephritis, urinary retention 3
Post-Imaging Management Algorithm
If CT Confirms Appendicitis
- Initiate broad-spectrum IV antibiotics immediately covering anaerobic bacteria 1
- Obtain immediate surgical consultation for appendectomy 1
- Admit the patient for surgical intervention 4
If CT Identifies Alternative Diagnosis
- For cecal or right-sided colonic diverticulitis: Start IV antibiotics, implement bowel rest, and obtain surgical consultation if complicated features present 1
- For bowel obstruction: NPO status, nasogastric decompression, IV fluids, and surgical consultation 1
- For gynecologic pathology: Urgent gynecology consultation for ovarian torsion or ectopic pregnancy 1
Critical Pitfalls to Avoid
Never use ultrasound first in obese patients, elderly patients, or when clinical suspicion for appendicitis is high—proceed directly to CT to avoid diagnostic delay 1. This is a common error that leads to missed diagnoses and increased morbidity.
Do not assume normal laboratory values exclude serious pathology, particularly in elderly patients who frequently present with normal white blood cell counts despite perforation or serious infection 1. The American Geriatrics Society emphasizes that atypical presentations are the norm in this population, with blunted inflammatory responses and higher perforation rates 1.
Avoid ordering CT without IV contrast unless there is a specific contraindication, as critical findings such as wall enhancement, adjacent liver parenchymal hyperemia, and vascular complications cannot be detected without contrast 2. The exception is suspected nephrolithiasis, where noncontrast CT is preferred.
Do not delay surgical consultation while waiting for imaging if clinical examination strongly suggests appendicitis with peritoneal signs 1. Time to surgery directly impacts perforation rates and mortality.
Special Population Considerations
Elderly Patients
- Expect atypical presentations with absent fever, minimal tenderness, and normal laboratory values despite serious pathology 1
- Lower threshold for advanced imaging as physical examination is less reliable 1
- Higher index of suspicion for malignancy, which accounts for 60% of large bowel obstructions in this population 1
Women of Reproductive Age
- Always obtain beta-hCG before imaging to exclude pregnancy and guide imaging choices 1
- Maintain high suspicion for gynecologic causes, which may mimic appendicitis 1
- Consider MRI without contrast as an alternative to CT to avoid radiation exposure in pregnant patients, with 97% sensitivity for appendicitis 2