The NICE guidelines define idiopathic (functional) constipation as "the subjective complaint of passage of abnormally delayed or infrequent passage of dry, hardened faeces often accompanied by straining and/or pain. It may also be associated with soiling, defined as involuntary passage of fluid or semi-solid stool into clothing, usually as a result of overflow from a faecally loaded bowel.” (1). The term idiopathic means the underlying cause cannot be explained