LAUSR

CASE A 48-year-old nurse with an alcohol use disorder history was being monitored in a professionals health program. She consistently produced low-to-moderate urinary ethyl sulfate (EtS) concentrations in the absence of detectable urinary ethyl glucuronide (EtG), blood phosphatidylethanol (PEth), and breath alcohol. She denied intentional ethanol consumption. DISCUSSION After prolonged monitoring in a drug treatment program, including a period in a controlled environment, we concluded that this individual's urinary EtS likely resulted from anatomical and microbial factors related to Roux-en-Y gastric bypass surgery, with possible contributions from hidden dietary sources of ethanol. We have no definitive explanation for the lack of urinary EtG.