Manometric evaluation of constipation--Part I.

Tests of anorectal function have evolved into clinically useful investigations, and they should no longer be regarded as esoteric tools. This transformation has led to major advances in understanding, diagnosis, and treatment of defecation disorders, such as constipation. Because constipation is a heterogeneous condition, it cannot be assessed by a single test. Judicious use of anorectal manometry, colon transit study, a test of simulated defecation, and defecography may provide invaluable pathophysiological information. Undoubtedly, examination of rectal and anal pressure activity, rectal sensation, rectoanal reflexes, and the functional morphology of the defecation unit provides more information than any other test of gastrointestinal motor function; however, there is no uniform criteria for defining manometric abnormalities. There is also an urgent need for establishing international standards for manometric techniques and for diagnosis. Nevertheless, knowledge and experience have paved the way for innovative diagnostic techniques and therapeutic approaches for patients with constipation.