Constipation study for back surgery patients withdrawn before starting

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Experimental Group (initial screen): * Age 18 years or older * Inpatient who will undergo a 1-2 level ALIF procedure with Dr. Richard Meyrat * Are not pregnant or lactating * Does not have a history of drug abuse within the past 2 years * Does not have a gastrointestinal ostomy Experimental Group (post-operative OIC screen/rescreen) * Actively constipated (i.e., no BM in last 48 hours, difficult having a spontaneous BM, or inability to have a spontaneous BM) * Receiving mu-agonist opioids * Expected to require daily opioid analgesics for at least 7 days following enrollment * Have not received or discontinued use of any laxatives, enemas and/or promotility agents within 48 hours of enrollment and the first dose of RELISTOR. Stool softeners are permitted. * Does not have a known hypersensitivity to methylnaltrexone, naltrexone, or naloxone Observational Group (initial screen): * Age 18 years or older * Inpatient who will undergo 1-2 level ALIF procedure with Dr. Graham * Are not pregnant or lactating * Does not have a history of drug abuse within the past 2 years * Does not have a gastrointestinal ostomy Observational Group (post-operative OIC screen/rescreen): * Actively constipated (i.e. no BM in last 48 hours, difficulty having a spontaneous BM, or inability to have a spontaneous BM) * Receiving mu-agonist opioids * Expected to require daily opioid analgesics for at least 7 days following enrollment Exclusion Criteria: Experimental Group (post-operative OIC screen/rescreen): Exclude patients with: * Fecal impaction * Mechanical bowel obstruction * Constipation not attributed to post-procedural opioid use * Calculated creatinine clearance less than 50 mL/min * Corrected QT interval greater than 500 msec. on a 12-lead screening electrocardiogram Observational Group (post-operative OIC screen/rescreen): Exclude patients with: * Fecal impaction * Mechanical bowel obstruction * Constipation not attributed to post-procedural opioid use