Background ROME IV diagnostic criteria describes functional gallbladder disorder (FGBD) as biliary pain in the absence of gallstones, supported by low ejection fraction on gallbladder scintigraphy. However, clinicians have noticed histological analysis of gallbladders to intermittently reveal cholelithiasis. Our study aims to quantify this and to reduce misdiagnosis rates of FGBD. Methods We performed a single centre, retrospective cohort study at St John of God Midland Hospital in Western Australia, Perth on 504 consecutive patients undergoing hepatobiliary iminodiacetic acid (HIDA) scan between 1 November 2015 to 1 April 2024. Results 5.3% (27/512) of patients had FGBD diagnosed pre-operatively by ROME IV. Of this, 18.5% (5/27) were noted to have histopathological cholelithiasis despite pre-operative imaging suggesting otherwise. Of the 22 patients with true gallbladder dysfunction, 70% (7/10) had resolution of symptoms after cholecystectomy, with remaining 30% (3/10) experiencing persisting symptoms and referred on for further medical workup. 5 had private followup and 7 did not attend follow-up appointments. Ultrasonography had a sensitivity at 64% and specificity of 88% for identifying cholelithiasis, with a negative predictive value of 81.48%. Conclusion FGBD remain a rare but not insignificant contributor to patients with undifferentiated abdominal pain. In the setting of microlithiasis, 2 in 10 patients will have gallstones missed on pre-operative imaging. Not only does this emphasise the importance of considering functional aspects of biliary pain in the absence of structural pathologies, but also being aware of the limitations of imaging to reduce the morbidity false negatives can confer.