Constipation Investigation History and physical examination Perform a careful DRE with an assessment of pelvic floor motion during simulated evacuation in patients with chronic constipation before referring for anorectal manometry, recognizing that a normal DRE does not exclude defecatory disorders. B Laboratory tests Obtain a CBC as part of the initial evaluation of patients with chronic constipation. B Do not obtain metabolic tests (glucose, calcium, TSH) as part of the initial evaluation of chronic constipation, unless other clinical features warrant otherwise. D Colonoscopy AGA Q Does the patient have alarm features (blood in the stool, anemia, weight loss)? Yes Consider the need for lower gastrointestinal endoscopy. No Do not perform colonoscopy for the evaluation of patients with constipation in the absence of alarm features (such as blood in stools, anemia, or weight loss), unless age- appropriate colon cancer screening has not been performed. D Avoidance of causative agents Discontinue medications that can cause constipation, if feasible, before obtaining further testing for constipation. B Anorectal physiology testing AGA Q Does the patient fail to respond to initial treatment? Yes Obtain anorectal manometry and rectal balloon expulsion test in patients not responding to laxatives. B No Do not perform colonoscopy for the evaluation of patients with constipation in the absence of alarm features (such as blood in stools, anemia, or weight loss), unless age- appropriate colon cancer screening has not been performed. D Avoidance of causative agents Discontinue medications that can cause constipation, if feasible, before obtaining further testing for constipation. B Anorectal physiology testing AGA Q Does the patient fail to respond to initial treatment? No Continue current management and follow-up as appropriate. Yes Obtain anorectal manometry and rectal balloon expulsion test in patients not responding to laxatives. B Defecography AGA Q Do anorectal tests show a defecatory disorder? Yes Manage the defecatory disorder appropriately. No Evaluate colonic transit if anorectal test results do not show a defecatory disorder or if symptoms persist despite treatment of a defecatory disorder. B Consider obtaining defecography (using barium radiographs or MRI) when the results of anorectal manometry and rectal balloon expulsion are inconclusive for defecatory disorders. B Do not obtain defecography before anorectal manometry and rectal balloon expulsion test. D