Diagnosis of constipation

The term constipation means different things to different people. A complaint of constipation can represent a disorder of colonic transit, rectal evacuation, rectal perception or an individual’s expectations of their bowels. In the Western world, constipation is estimated to affect approximately 15% of adults and 9% of children, and costs healthcare systems billions of dollars per annum. The diagnosis of constipation is relatively simple and based on a patient’s symptoms. For example, if a patient seeking medical help reports that they are dissatisfied with their ability to expel stool or they are unable to use their bowel without the aid of laxatives, then they are, more likely than not, constipated. From a physician’s point of view, consensus statements, such as the Rome III criteria, have been produced to help with the clinical diagnosis of constipation. The diagnosis of the different types of constipation is more complex. Constipation is commonly subdivided into slow-transit constipation (sometimes referred to as colonic inertia), rectal evacuation disorder (also referred to as outlet obstruction, pelvic floor dysfunction/dyssynergia or outlet delay), normal transit constipation or a group with constipation and abdominal pain/bloating, which encompasses irritable bowel syndrome (IBS). While symptoms can play a role in helping to define these categories, the subtyping of constipation is usually established by various investigative measures including anorectal manometry, defecography, rectal sensitivity testing, measures of colonic transit and, in children, colonic manometry. This chapter will provide a brief overview of some of the more common and recent diagnostic tests for constipation, detailing what information they provide and their limitations.