Specialty laboratory testing for chronic abdominal pain in irritable bowel syndrome.

BACKGROUND

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder seen by both primary care providers (PCPs) and gastroenterologists, and further diagnostic testing is generally discouraged unless red-flag symptoms are present.

AIMS: Examine if advanced serologic testing for chronic abdominal pain in IBS patients followed society-specific guidelines and evaluate the diagnostic accuracy of these tests.

METHODS

The study involved a retrospective cross-sectional analysis of adults aged 18 and older who were seen at our institution between 2013 and 2018. Tests included: C1 esterase inhibitor, MEFV gene, urine porphobilinogen, anti-dsDNA, and heavy metal screening. Patients with preexisting rheumatological conditions or diagnoses such as hereditary angioedema, porphyria, familial Mediterranean fever, or lead poisoning were excluded. An appropriateness scale based on disease-specific guidelines was used to evaluate test suitability.

RESULTS

Among 26,732 IBS patients, 143 underwent advanced laboratory testing, with 85.3% ordered by gastroenterologists. Only 12.5% of tests adhered to society-specific guidelines, and the positive test rate was 2.1%. The total cost of testing was $46,542, with $39,007 spent on tests deemed inappropriate.

CONCLUSIONS

The findings emphasize the effectiveness and importance of adhering to Rome IV criteria, as advanced testing often fails to improve diagnostic accuracy and increases unnecessary healthcare costs.