In the Gray Zone: Few Patients Proceed to Additional Testing After Equivocal Anorectal Manometry and Balloon...

Anorectal manometry (ARM) and balloon expulsion testing (BET) are often first-line tests to diagnose dyssynergic defecation (DD), followed by either barium or MR defecography if results are equivocal for a defecatory disorder. However, real-world outcomes for these patients are unclear. We aim to characterize patterns of patient treatment after equivocal results on ARM and BET.

A retrospective chart review was conducted of patients who obtained ARM and BET at a single referral motility center between January 2024 and February 2025. Demographic data, results of ARM, BET, and MR defecography if obtained were recorded along with the treatment plan at follow-up.

Of 409 charts reviewed, 97 patients with equivocal results were included in the study (81.4% female; mean age of 51.6 ± 18.0) and MR defecography was obtained by 30.9% of patients. Of these, 50.0% had findings consistent with DD and 56.7% had significant structural or anatomic abnormalities. Of the remaining 67 patients (69.1%) who did not obtain MR defecography, 31.3% opted for an empiric trial of biofeedback or pelvic physical therapy (PT), 26.9% continued with optimized medical management alone, whereas 14.4% were lost to follow-up.

Fewer than one third of patients obtain MR defecography within 6 months of equivocal ARM and BET; almost half of those had results corroborating a diagnosis of DD or significant structural abnormalities on MR defecography. Among patients who did not obtain MR defecography, most opted for an empiric trial of biofeedback/pelvic PT or optimized medical management. More research is needed to identify which patients will substantively benefit from additional confirmatory testing when there are equivocal results.