What testing is indicated for a 45-year-old woman with intermittent right lower quadrant abdominal pain radiating to the flank?

From the Guidelines

For a 45-year-old woman with intermittent right lower quadrant abdominal pain radiating to the flank, I strongly recommend a CT abdomen and pelvis with contrast as the initial diagnostic imaging modality. This recommendation is based on the high diagnostic yield of CT scans for detecting appendicitis and other alternative diagnoses, as reported in the 2022 update of the ACR Appropriateness Criteria for right lower quadrant pain 1. The study highlights the excellent diagnostic performance of CT scans, with a sensitivity of 95% and specificity of 94% for detecting appendicitis.

The patient's symptoms of intermittent right lower quadrant abdominal pain radiating to the flank suggest a broad differential diagnosis, including gynecological conditions, urological issues, gastrointestinal causes, and musculoskeletal problems. The radiation to the flank raises concern for possible renal origin, making urological evaluation particularly important.

• Initial testing should include:
  • Complete blood count
  • Comprehensive metabolic panel
  • Urinalysis
  • Urine culture
• Imaging studies should include:
  • CT abdomen and pelvis with contrast to evaluate for appendicitis, kidney stones, or other abdominal pathologies
  • Pelvic and transvaginal ultrasound to assess for ovarian pathology, fibroids, or other gynecological causes
• If pain persists, consider:
  • Colonoscopy to rule out inflammatory bowel disease or diverticulitis
  • CA-125 testing if ovarian pathology is suspected

The use of CT abdomen and pelvis without IV contrast may be appropriate for evaluating urolithiasis, but the addition of IV contrast is necessary to evaluate for other causes of abdominal pain, as reported in the 2023 update of the ACR Appropriateness Criteria for acute pelvic pain in the reproductive age group 1. The 2023 update of the ACR Appropriateness Criteria for acute onset flank pain-suspicion of stone disease also supports the use of CT abdomen and pelvis without IV contrast for initial imaging, but recommends the use of CT abdomen and pelvis with IV contrast for follow-up imaging or in patients with a negative history of renal stones 1.

However, based on the most recent and highest quality study, CT abdomen and pelvis with contrast is the recommended initial diagnostic imaging modality for a 45-year-old woman with intermittent right lower quadrant abdominal pain radiating to the flank, as it provides a comprehensive evaluation of the abdomen and pelvis, including the detection of appendicitis, kidney stones, and other abdominal pathologies 1.

From the Research

Testing for Abdominal Pain

The patient's symptoms of intermittent right lower quadrant abdominal pain radiating to the flank can be indicative of several conditions.

• The study 2 highlights the importance of considering rare causes of abdominal pain, such as intestinal malrotation, Fitz-Hugh-Curtis syndrome, and appendicular neuroendocrine tumors, in the differential diagnosis.
• Initial laboratory workup may include a complete blood count, basic metabolic panel, urinalysis, and C-reactive protein measurement, as suggested in the study 3 for diverticulitis.
• Imaging modalities such as computed tomography with intravenous contrast may be used to confirm diagnosis and assess for complications, as mentioned in 3.
• The study 4 emphasizes the need for awareness of rare causes of recurrent abdominal pain and provides expert recommendations for recognition, diagnosis, and management.
• A thorough physical examination, including abdominal examination, and laboratory studies, such as urine culture and blood tests, may help identify the underlying cause of the patient's symptoms, as seen in the study 5.
• A multimodal approach, including pelvic floor muscle training, biofeedback, and electrical stimulation, may be beneficial in managing symptoms of neurogenic bladder and bowel dysfunction, as reported in the study 6.

Possible Tests

Possible tests for the patient's condition may include:

• Complete blood count
• Basic metabolic panel
• Urinalysis
• C-reactive protein measurement
• Computed tomography with intravenous contrast
• Urine culture
• Blood tests, such as hemoglobin, white blood cell count, and creatinine
• Thyroid function testing, if hyperthyroidism is suspected
• Pelvic floor muscle training and biofeedback, if neurogenic bladder and bowel dysfunction are suspected