Effect of Naloxegol on Gastric, Small Bowel, and Colonic Transit in Healthy Subjects

Inclusion criteria: * Body Mass Index (BMI) between 19 and 30 kg/m\^2 and absolute weight between 45 and 100 kg. for both males and females. * Females who are non-pregnant, non-lactating, postmenopausal for at least one year (as evidenced by last menses 12 months from Day 0), surgically sterile, or willing to use a clinically-approved method of contraception from 35 days prior to Day 0 until 30 days after the last dose of study medication * Males who are surgically sterile or willing to use a clinically approved method of contraception from Day 0 until 30 days after the last dose of study medication. * Absence of gastrointestinal symptoms unless deemed not clinically significant by the Investigator. * Able to understand and willing to sign informed consent * Negative urine drug screen at screening Exclusion criteria: * Structural or metabolic diseases/conditions that affect the gastrointestinal system, or functional gastrointestinal disorders. For screening, three or more "YES" responses on the Bowel Disease Questionnaire will be used to exclude subjects with irritable bowel syndrome. * Use of drugs or agents within the past 2 weeks or planned use in the subsequent 4 weeks during the study period that: Alter GI transit including laxatives, magnesium or aluminum-containing antacids, prokinetic, erythromycin, narcotics, anticholinergics, tricyclic antidepressants, Selective serotonin re-uptake inhibitors (SSRI) and newer antidepressants. * Analgesic drugs including opiates, …