Anorectal probe apparatus having at least one muscular activity sensor

An apparatus for sensing muscular activity of the rectosigmoid region, rectum, and the anorectal canal of a subject is disclosed. This apparatus includes an elongate probe having a distal end opposing a proximal end which is configured for insertion into the patient's anorectal canal and includes a pressure sensor, an electromyography sensor, and a stimulus balloon. Multiple pressure sensors may be included to evaluate muscular activity in the anorectal canal. In addition, pressure sensors may be distributed along the length of the probe to simultaneously measure the response of other portions of the anorectal canal besides the anal sphincter muscle. A pressure sensor is also located inside the stimulus balloon for monitoring intraballoon pressure.