Effects of neostigmine and atropine on motor activity of ileum, colon, and rectum of anaesthetized subjects.

In unanaesthetized patients atropine and neostigmine in doses normally used by anaesthetists to reverse muscle relaxants produced a pronounced increase in bowel activity. This response occurred whether atropine was given before or simultaneously with neostigmine.The response still occurred in 38% of patients anaesthetized without halothane, and possibly this increase in motility might endanger a recently constructed anastomosis. The ileum appeared particularly prone to neostigmine stimulation, and anastomoses involving ileum would seem especially at risk. When halothane was used during anaesthesia the response was completely inhibited during the period studied.