Neostigmine increases postoperative colonic motility in patients undergoing colorectal surgery

Background. Gastrointestinal motility is frequently impaired after abdominal surgery. We investigated the effects of neostigmine on colonic motility in patients after colorectal surgery and in healthy volunteers. Methods. Colonic motility was recorded by a manometry/barostat system in 12 patients after left colonic or rectal resection during baseline and after the intravenous administration of increasing doses of neostigmine on postoperative days 1, 2, and 3. In addition, colonic motility was recorded in 7 healthy volunteers. Results. Neostigmine increased the colonic motility index. This increase was from 135 +/- 28 mm Hg/min at baseline to 574 +/- 219 mm Hg/min after administration of 5 mug/kg neostigmine on day 3 after surgery (mean +/- SEM, P < .05). In healthy volunteers, neostigmine at a dose of 5 mug/kg increased the colonic motility index from 184 +/- 73 to 446 +/- 114 mm Hg/min (P < .05). Barostat bag volumes decreased dose-dependently after neostigmine administration in patients as well as in volunteers, indicating an increase in colonic tone. Conclusions. Colonic motility and tone increased after neostigmine administration at a dose of 5 mug/kg in postoperative patients and in healthy volunteers. Neostigmine can be used to stimulate colonic motility after colorectal surgery and has a similar effect postoperatively as in healthy volunteers.