eMedicine Specialties > Gastroenterology > Colon
Constipation: Differential Diagnoses & Workup
Updated: Jan 28, 2010
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Differential Diagnoses
Other Problems to Be Considered
Psychological causes
Workup
Laboratory Studies
- Laboratory evaluation does not play a large role in the initial assessment of the patient.
- Check thyroid-stimulating hormone levels to rule out hypothyroidism in patients refractory to dietary management.
- Determine serum electrolyte profile, including potassium, calcium, glucose, and creatinine, in patients with recent-onset constipation to assess an acute electrolyte imbalance and in chronically constipated patients for whom initial medical treatment has failed.
- Fecal occult blood should be tested in chronically constipated middle-aged or elderly adults to assess an obstructing neoplasm of the colon.
- Leukocyte count is useful for patients presenting with abdominal pain or fever or providing any indication that the constipation is secondary to an ileus. This may lead to further, more aggressive evaluation.
Imaging Studies
- Imaging studies are used to rule out acute processes that may be causing colonic ileus or to evaluate causes of chronic constipation.
- In patients with acute abdominal pain, fever, leukocytosis, or other symptoms suggesting possible systemic or intra-abdominal processes, imaging studies are used to rule out sources of sepsis or intra-abdominal problems.
- Order an upright chest roentgenogram and a flat and upright abdominal film. The abdominal film may reveal a colon full of stools, confirming the diagnosis of obstipation.
- Abdominal CT scan may be indicated to further evaluate the possibility of an intra-abdominal abscess.
- Acute constipation in the setting of an empty rectal vault and a proximal colon that is dilated with air or stool suggests large bowel obstruction, which should be further evaluated via Gastrografin enema or lower GI endoscopy.
- Gastrografin enema has the advantage of acting as an osmotic laxative, which may aid in the evacuation of the colonic contents.
- Air contrast barium enema is useful to assess the possibility of an obstructing colon cancer, intermittent volvulus, or colonic stricture in the setting of chronic constipation.
- A barium study is preferable to Gastrografin for patients who do not present with an acute process. On the other hand, Gastrografin is preferable for patients with an acute abdomen because this prevents the risk of extravasation of barium into the peritoneal cavity through a perforated diverticulum or colon cancer.
- In patients with suspected colonic obstruction, the author prefers to use colonoscopy instead of barium enema, but either may suffice.
- Defecography should be performed if an obstruction is suspected at the level of the anal canal.
- Fill the rectosigmoid with barium paste and fluoroscopically observe the act of defecation.
- This test may demonstrate alterations in the anorectal angle during defecation, presence of pelvic floor weakness,2 or transient rectal prolapse or intussusception.
- Controlled pressure-based rectal distension with fluoroscopic rectal imaging to measure the rectal diameter at the minimal distension pressure may be useful in identifying idiopathic megabowel in the absence of an organic cause of other problems.7
- Conversely, colonic transit time should be determined in patients suspected to have colonic motility disorder.
- Accomplish this by observing the passage of orally administered radiopaque markers via daily abdominal roentgenograms.
- Record the time taken for the passage of the markers and the site where they appear to be retained.
- A patient with outlet obstruction tends to retain the markers in the left colon and sigmoid, while a patient with colonic dysmotility may retain the markers throughout the colon.
Procedures
- Lower GI endoscopy, anorectal manometry, electromyography, and balloon expulsion may be used in the evaluation of constipation.
- Lower GI endoscopy is useful in patients who are acutely constipated if large bowel obstruction is suspected based on an empty rectal vault and a distended proximal colon.
- Colonoscopy should not be performed if perforation or acute diverticulitis or other infectious processes are suspected because of the risk of worsening intra-abdominal contamination caused by colonic distension during the procedure.
- In the acute setting, bowel preparation is either not used or, at the most, 1-2 gentle enemas are used.
- Rigid endoscopy may be used in an urgent situation when flexible endoscopy is not available.
- Flexible endoscopy is generally preferred over rigid endoscopy because the former is more comfortable for the patient, provides a better view for the endoscopist, and permits access to more of the colon.
- Advance the flexible endoscope into the rectosigmoid until the site of the obstruction is reached or until the splenic flexure is identified, which suggests the absence of a rectosigmoid obstruction.
- If the initial sigmoidoscopy reveals no abnormal findings or if the constipation is more chronic, the patient should subsequently undergo a standard oral bowel preparation and either colonoscopy (the author's preference) or air contrast barium enema to more fully evaluate the remainder of the colon.
- Deep rectal biopsy, sometimes with double or triple bite techniques, may be used to diagnose Hirschsprung disease.
- Anorectal manometry documents several parameters. Interpreting the results of this test is complex and varies with the center performing the test. Consult a specialist familiar with the local testing facilities. These parameters include the following:
- External anal sphincter and puborectalis muscle function
- Reflex relaxation of the internal sphincter when the rectum is distended
- Coordination of these muscles during the bear-down phase of defecation
- Anorectal pressures during these events
- The threshold at which rectal distension is perceived
- Electromyography
- This study documents paradoxical external sphincter or puborectalis spasm during defecation, consistent with the diagnosis of anismus.
- It is useful during subsequent biofeedback training because the patient is taught to relax these muscles.
- Balloon expulsion
- A balloon filled with varying amounts of water is rectally inserted. The patient is asked to expel the balloon.
- Decreased ability to expel a balloon filled with 150 mL of water suggests decreased defecatory ability.
- Manual disimpaction and transrectal enemas may be used after any critical illness associated with constipation has been ruled out.
Histologic Findings
Findings include the histology of any obstructing colonic lesion (eg, neoplasms, strictures from Crohn disease, diverticulitis, ischemia) and the agangliosis of Hirschsprung disease.
More on Constipation |
| Overview: Constipation |
 Differential Diagnoses & Workup: Constipation |
| Treatment & Medication: Constipation |
| Follow-up: Constipation |
| References |
| Further Reading |
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References
Peppas G, Alexiou VG, Mourtzoukou E, et al. Epidemiology of constipation in Europe and Oceania: a systematic review. BMC Gastroenterol. Feb 12 2008;8:5. [Medline].
Amselem C, Puigdollers A, Azpiroz F, Sala C, Videla S, Fernández-Fraga X, et al. Constipation: a potential cause of pelvic floor damage?. Neurogastroenterol Motil. Sep 17 2009;[Medline].
Bouras EP, Tangalos EG. Chronic constipation in the elderly. Gastroenterol Clin North Am. Sep 2009;38(3):463-80. [Medline].
Noguera A, Centeno C, Librada S, Nabal M. Screening for Constipation in Palliative Care Patients. J Palliat Med. Sep 11 2009;[Medline].
Taghavi SA, Shabani S, Mehramiri A, Eshraghian A, Kazemi SM, Moeini M, et al. Colchicine is effective for short-term treatment of slow transit constipation: a double-blind placebo-controlled clinical trial. Int J Colorectal Dis. Aug 25 2009;[Medline].
Uher R, Farmer A, Henigsberg N, Rietschel M, Mors O, Maier W, et al. Adverse reactions to antidepressants. Br J Psychiatry. Sep 2009;195(3):202-10. [Medline].
Gladman MA, Knowles CH. Novel concepts in the diagnosis, pathophysiology and management of idiopathic megabowel. Colorectal Dis. Jul 2008;10(6):531-8; discussion 538-40. [Medline].
Hsiao KC, Jao SW, Wu CC, et al. Hand-assisted laparoscopic total colectomy for slow transit constipation. Int J Colorectal Dis. Apr 2008;23(4):419-24. [Medline].
Tomita R, Fujisak S. Minilaparotomy with a gasless laparoscopic-assisted procedure by abdominal wall lifting for ileorectal anastomosis in patients with slow transit constipation. Hepatogastroenterology. Jul-Aug 2009;56(93):1022-7. [Medline].
Frascio M, Stabilini C, Ricci B, et al. Stapled transanal rectal resection for outlet obstruction syndrome: results and follow-up. World J Surg. Jun 2008;32(6):1110-5. [Medline].
Bona S, Battafarano F, Fumagalli Romario U, et al. Stapled anopexy: postoperative course and functional outcome in 400 patients. Dis Colon Rectum. Jun 2008;51(6):950-5. [Medline].
van den Esschert JW, van Geloven AA, Vermulst N, et al. Laparoscopic ventral rectopexy for obstructed defecation syndrome. Surg Endosc. Mar 5 2008;[Medline].
Mowatt G, Glazener C, Jarrett M. Sacral nerve stimulation for fecal incontinence and constipation in adults: a short version Cochrane review. Neurourol Urodyn. 2008;27(3):155-61. [Medline].
Holzer B, Rosen HR, Novi G, et al. Sacral nerve stimulation in patients with severe constipation. Dis Colon Rectum. May 2008;51(5):524-29; discussion 529-30. [Medline].
Camilleri M, Beyens G, Kerstens R, Robinson P, Vandeplassche L. Safety assessment of prucalopride in elderly patients with constipation: a double-blind, placebo-controlled study. Neurogastroenterol Motil. Sep 9 2009;[Medline].
Layer P, Keller J, Loeffler H, et al. Tegaserod in the treatment of irritable bowel syndrome (IBS) with constipation as the prime symptom. Ther Clin Risk Manag. Mar 2007;3(1):107-18. [Medline].
Alonso-Coello P, Mills E, Heels-Ansdell D, et al. Fiber for the treatment of hemorrhoids complications: a systematic review and meta-analysis. Am J Gastroenterol. Jan 2006;101(1):181-8. [Medline].
Biggs WS, Dery WH. Evaluation and treatment of constipation in infants and children. Am Fam Physician. Feb 1 2006;73(3):469-77. [Medline].
Brown SR. Tegaserod for chronic constipation. J Fam Pract. Dec 2005;54(12):1060, 1063. [Medline].
Di Palma JA. Expert commentary--new developments in the treatment of constipation. MedGenMed. Jan 1 2005;7(1):17. [Medline].
Fotter R. Imaging of constipation in infants and children. Eur Radiol. 1998;8(2):248-58. [Medline].
Griffin GC, Roberts SD, Graham G. How to resolve stool retention in a child. Underwear soiling is not a behavior problem. Postgrad Med. Jan 1999;105(1):159-61, 165-6, 172-3. [Medline].
Johanson JF. Geographic distribution of constipation in the United States. Am J Gastroenterol. Feb 1998;93(2):188-91. [Medline].
Johanson JF, Sonnenberg A, Koch TR. Clinical epidemiology of chronic constipation. J Clin Gastroenterol. Oct 1989;11(5):525-36. [Medline].
Lennard-Jones JE. Clinical management of constipation. Pharmacology. Oct 1993;47 Suppl 1:216-23. [Medline].
Ludwig KA. Management of colorectal-anal dysfunction. Obstet Gynecol Clin North Am. Dec 1998;25(4):923-44, viii. [Medline].
Nyam DC, Pemberton JH. Current advances and controversies in the surgical therapy for anorectal motility disorders. Dig Dis. 1997;15 Suppl 1:93-103. [Medline].
Nygaard IE. Pharmacologic management of pelvic floor dysfunction. Obstet Gynecol Clin North Am. Dec 1998;25(4):867-82. [Medline].
Sandler RS, Jordan MC, Shelton BJ. Demographic and dietary determinants of constipation in the US population. Am J Public Health. Feb 1990;80(2):185-9. [Medline].
Shelton AA, Welton ML. The pelvic floor in health and disease. West J Med. Aug 1997;167(2):90-8. [Medline].
Simpson BB, Ryan DP, Schnitzer JJ, et al. Surgical evaluation and management of refractory constipation in older children. J Pediatr Surg. Aug 1996;31(8):1040-2. [Medline].
Stark ME. Challenging problems presenting as constipation. Am J Gastroenterol. Mar 1999;94(3):567-74. [Medline].
Whitehead WE. Psychosocial aspects of functional gastrointestinal disorders. Gastroenterol Clin North Am. Mar 1996;25(1):21-34. [Medline].
Zuckerman MJ. The role of fiber in the treatment of irritable bowel syndrome: therapeutic recommendations. J Clin Gastroenterol. Feb 2006;40(2):104-8. [Medline].
Further Reading
Clinical guidelines
Functional constipation and soiling in children.
University of Michigan Health System - Academic Institution. 1997 Sep (revised 2008 Sep). 15 pages. NGC:006843
ASGE guideline: guideline on the use of endoscopy in the management of constipation.
American Society for Gastrointestinal Endoscopy - Medical Specialty Society. 2005 Aug. 3 pages. NGC:004485
Prevention of constipation in the older adult population.
Registered Nurses' Association of Ontario - Professional Association. 2002 Jan (revised 2005 Mar). 56 pages. NGC:004213
Practice parameters for the evaluation and management of constipation.
American Society of Colon and Rectal Surgeons - Medical Specialty Society. 2007 Dec. 10 pages. NGC:006460
Clinical trials
An Open-Label, Long-Term Safety Study of Linaclotide in Patients With Chronic Constipation or Irritable Bowel Syndrome With Constipation
Intestinal Microecology in Chronic Constipation
Lubiprostone (Amitiza®) Vs. Standard Care in Opioid-Induced Constipation After Surgery in Inpatient Rehabilitation
Effectiveness of Docusate in Preventing/Treating Constipation in Palliative Care Patients
Related eMedicine topics
Constipation (Pediatrics: General Medicine)
Constipation (Emergency Medicine)
Constipation and Bowel Management
Hirschsprung Disease
Rectal Prolapse
Keywords
constipation, bowel movement, diverticular disease, defecation, anorectal manometry, hemorrhoid, anal fissure, hemorrhoidal disease, thrombosis hemorrhoid, rectal tumor, bowel motility, laxative abuse, colonic tumor, rectal prolapse, colonic ileus, obstipation, defecography, anismus, large bowel obstruction, ischemic bowel
