ABSTRACT
Human defaecation involves integrated and coordinated sensorimotor functions, orchestrated by central, spinal, peripheral and enteric neural activities, acting on a morphologically intact gastrointestinal tract. From the mid-1960s through to the early 1980s, several tests were developed to study colonic and anorectal function. Patients with disorders of colonic motility typically present with symptoms of constipation or diarrhoea, and it has long been known that watery stools are equated with accelerated and hard stools with prolonged intestinal transit. As disorders of colonic motility often affect gut transit times, the availability of methods to quantify intraluminal movement are of significant diagnostic importance, and may help to guide appropriate therapies. In patients with chronic constipation, evaluation of gut transit, together with assessment of rectal evacuation and sensation, is recognised as the cornerstone of specialist investigation. A radio-opaque marker study is recommended for clinical evaluation of colonic transit time in subjects with constipation and irritable bowel syndrome.
