The effect of ketamine anesthesia on anorectal manometry

Two hundred and twenty-five patients aged from neonate to 15 years presenting with chronic constipation and soiling had anorectal manometry without sedation, and 142 patients in the same age range and with a similar range of presenting complaints had anorectal manometry using ketamine as an anesthetic. There were no significant differences between the groups in the resting pressures recorded in the anal canal, in the amount of inhibition with rectal distension, or in the frequency or amplitude of rhythmical activity of the internal anal sphincter. Classical inhibitory troughs were seen when expected in both groups as were signs of external sphincter activity. Ketamine anaesthesia is a suitable sedative which enables anorectal manometry to be performed on young or nervous patients and does not alter the qualitative or quantitative responses.