Evaluation of Constipation

Educational Objectives

The goal of this program is to improve the management of constipation. After hearing and assimilating this program, the clinician will be better able to:

1. Evaluate the role of defecography, colonic transit scintigraphy, and anal manometry in patients with constipation.

2. Develop and implement an algorithm for the treatment of patients with constipation.

Summary

Rome IV criteria for diagnosis of constipation: straining during >25% of defecations; lumpy or hard stools in >25% of defecations; sensation of incomplete evacuation; anorectal obstruction; manual maneuvers required for defecation; stool frequency <3/wk; diagnosis requires presence of 2 symptoms for >3 mo and onset of symptoms >6 mo earlier

Types of Constipation

Primary idiopathic constipation: incidence higher in women than men; usually not associated with abdominal pain or bloating; reports of infrequent defecation and defecation requiring mechanical assistance common

Subgroups: normal colonic transit — defecation infrequent; patients unresponsive to laxatives or dietary fiber therapy; anorectal sensory and motor function may be abnormal; psychosocial distress may be present; slow transit constipation (colonic inertia) — colonic resting motility normal; motility not increased by laxatives and eating; dyssynergic defecation — inability to evacuate; probably acquired (learned) rather than organic or neurogenic

Secondary constipation: may be adverse effect of drugs, have congenital cause (eg, Hirschsprung disease), or due to obstruction (eg, cancer, strictures secondary to diverticulitis or irradiation), multiple sclerosis, Parkinson disease, Alzheimer disease, hypothyroidism, hypercalcemia, diabetes mellitus, psychiatric disorders (eg, anxiety, anorexia), or functional outlet obstruction (eg, rectocele, rectal prolapse)

Constipation-predominant irritable bowel syndrome (IBS): incidence in younger women high; symptoms — abdominal pain and bloating; pain relieved with bowel movement; alternation of diarrhea and constipation; straining to defecate

Evaluation of Constipation

Early evaluation: begins with thorough history and physical examination; systematic reviews of literature advise against laboratory, endoscopic, and radiologic investigations unless “alarm signs” present (eg, anemia; acute onset of symptoms; loss of weight; presence of occult blood in feces; family history of inflammatory bowel disease, cancer, or polyps); regardless of etiology, patients should undergo trial of dietary modification, fiber supplements, and laxatives before diagnostic workup

History: ask about frequency of defecation, characteristics of stool, use of aids to defecation (eg, digitation), pain, frequency of incomplete or unsuccessful evacuation, prolapse, bleeding, and use of dietary modifications, fiber supplements, and laxatives; fecal incontinence may be manifestation of constipation (overflow incontinence); 2-wk diary of bowel habits and food diary helpful; evaluate patient for secondary constipation by obtaining medical, obstetric, surgical, medication, and psychiatric history; studies found 15% to 35% incidence of sexual abuse in women with constipation

Physical examination: sensitivity and specificity of abdominal and anorectal examinations high (positive predictive value for pelvic dyssynergia 97%); note presence of anal wink, excoriation of anoderm, staining, stenosis, fissure, hemorrhoids, and prolapse of pelvic floor; digital examination evaluates resting tone, strength of squeeze, and relaxation of puborectal muscle; perform anoscopy and sigmoidoscopy

Laboratory tests: performed only for patients with alarm signs; measure levels of hemoglobin, glucose, creatinine, and calcium; include thyroid function test; colonoscopy recommended for patients >50 yr of age (or younger if personal or family history positive) and those with alarm signs, or if surgery for constipation under consideration

Defecography: barium defecography — performed as patient sits on commode; assesses anorectal structures, anorectal angle (change <15° abnormal), and descent of pelvic floor (<1 cm abnormal); key to diagnosis of pelvic floor dyssynergia; disadvantages include operator dependence, poor reliability, and low patient satisfaction; magnetic resonance (MR) defecography — yields more information than barium defecography; evaluates global anatomy of pelvic floor, dynamic motion, and morphology of sphincter; useful in diagnosis of intussusception; expensive and not widely available; studies have not found benefit compared with barium defecography, but patient satisfaction greater

Radiopaque marker test (eg, Sitzmarks test): patient swallows capsule containing 24 radiopaque rings; radiographs obtained on days 1 and 6; abnormal result >5 residual markers on day 6; distribution of markers throughout colon reflects colonic inertia (surgery effective); concentration of markers in rectum indicates pelvic outlet obstruction (biofeedback therapy effective)

Colonic transit scintigraphy: patient swallows pill containing radioisotope; gamma imaging performed 24 hr later; quantitative method to evaluate total and regional transit; expensive, not widely available, and lacks advantages over radiopaque marker study

Wireless motility capsule study: evaluates gastric emptying, small bowel transit, and whole-gut transit time; useful in patients suspected of having dysmotility of entire gastrointestinal tract (subtotal colectomy not beneficial and may result in anastomotic leak); sensitivity and specificity high; tolerated well and eliminates exposure to radiation of other tests; expensive

Other tests: manometry — important test; allows diagnosis of dyssynergia and abnormal rectal sensation; balloon expulsion test — simple test performed in office; patient asked to expel balloon inflated with 50 mL of fluid; can diagnose dyssynergia; dyssynergic defecation and slow transit constipation may overlap; barostat attached to balloon provides information on rectal sensation, tone, and compliance; assesses poor compliance of rectum in patients with IBS

Algorithm: gather history and perform physical examination; in absence of alarm signs, start trial of fiber supplements and modifications in lifestyle; if no improvement found, add lubiprostone (Amitiza) or linaclotide (Linzess); if no improvement found, consider workup; presence of alarm signs prompts immediate workup; workup includes manometry, balloon expulsion test, radiopaque marker test, and MR defecography; treat patients according to type of constipation

Readings

American College of Gastroenterology Chronic Constipation Task Force: An evidence-based approach to the management of chronic constipation in North America. Am J Gastroenterol 2005;100 Suppl 1:S1-4; Bharucha AE et al: American Gastroenterological Association technical review on constipation. Gastroenterology 2013 Jan;144(1):218-38; Paquette IM et al: The American Society of Colon and Rectal Surgeons’ Clinical Practice Guideline for the Evaluation and Management of Constipation. Dis Colon Rectum 2016 Jun;59(6):479-92; Pikarsky AJ et al: Long-term follow-up of patients undergoing colectomy for colonic inertia. Dis Colon Rectum 2001 Feb;44(2):179-83; Rao SS et al: Randomized controlled trial of biofeedback, sham feedback, and standard therapy for dyssynergic defecation. Clin Gastroenterol Hepatol 2007 Mar;5(3):331-8; Rao SS et al: Clinical utility of diagnostic tests for constipation in adults: a systematic review. Am J Gastroenterol 2005 Jul;100(7):1605-15.

Disclosures

For this program, members of the faculty and planning committee reported nothing to disclose.

Acknowledgements

Dr. Serur was recorded at the 3rd Annual Colon and Rectal CME Pelvic Floor Disorders, presented by the Icahn School of Medicine at Mount Sinai and held October 28, 2016, in New York, NY. For information on the 4th Annual Colon and Rectal CME Pelvic Floor Disorders, please visit icahn.mssm.edu/cme/courses. The Audio Digest Foundation thanks the speakers and sponsors for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

GS640102

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.