Naloxegol has recently been approved by the US Food and Drug Administration to treat opioid induced constipation in non-cancer chronic pain patients. Its effectiveness in acute care patients, however, is not known. Therefore, the researchers' goal is to investigate whether naloxegol is superior to osmotic laxatives for refractory constipation in ICU patients already receiving prophylactic stool softeners and simulant laxatives through a double-blind, randomized control trial.