Overview of testing of motility and of the anorectum

Evaluation of constipation begins with a detailed history and physical. Diagnostic testing for constipation is not routinely recommended in the initial evaluation in the absence of alarm signs. Testing should be targeted at symptoms or signs elicited in the history or physical that suggest an organic process. Colonoscopy is indicated in all patients over 50 years of age who have never had colorectal cancer screening and in those with alarm symptoms; experts suggest start screening at 45 years of age for African Americans and the obese due to diagnosis at a younger age. Anorectal manometry, along with the rectal balloon expulsion test, should be performed in patients who fail to respond to laxatives or empiric medical therapy for constipation. Additional testing, including defecography, dynamic pelvic magnetic resonance imaging, colon transit studies, colon manometry, and EMG, may also be used to further characterize the etiology and therapy of chronic constipation. The information herein is intended as a guide to diagnostic testing for those with constipation refractory to conservative treatment.