Emerging drugs for postoperative ileus.

Postoperative ileus (POI) is an impairment of coordinated gastrointestinal (GI) motility that develops as a consequence of abdominal surgery and is a major factor contributing to patient morbidity and prolonged hospitalization. Although the origin and cause of POI are poorly understood, it is known that abnormal GI motility associated with delayed gastric emptying and intestinal transit is a major factor leading to abdominal bloating, vomiting and lack of defecation. Furthermore, opioid drugs such as morphine, used for the management of postoperative pain, cause inhibition of bowel transit. Proposed mechanisms of POI include the stimulation of neuronal responses, such as excitation of afferent neurons and activation of noradrenergic, non-adrenergic and non-cholinergic neuronal pathways, as well as the induction of an intestinal inflammatory response. The development of new pharmacological strategies to prevent or reduce the frequency of POI is very important as existing approaches do not offer relief for most patients. This review describes emerging therapeutics that may advance the care of patients with POI.