Endoscopic evaluation of patients with constipation include flexible sigmoidoscopy and colonoscopy. Flexible sigmoidoscopy is the direct visualization of the rectum and sigmoid colon. However, colonoscopy is study of the whole colonlumen. Every patient with alarm signs have to be evaluated using colonoscopy. In younger patients, flexible sigmoidoscopy would be sufficient for further investigation of alarm signs. Colonic manometry is 24-hour measurement of pressure within the large bowel, using specific probes and portable recorders. Anorectalmanometry is studying the pressure activity of anorectum during rest and defecation, along with rectalsensation, rectoanal reflexes, and anal sphincter function. Balloon expulsion test is a simple bedside test to evaluate the ability of patient to evacuate the artificial stool. Rectal biostat test consists of a very compliant plastic balloon, which is inserted into the rectum, concurrently connected to computer device to measure the pressure.
Every subjects older than 50 years without previous screening for colon cancer
Every patient with alarm signs have to be evaluated using colonoscopy. In younger patients, flexible sigmoidoscopy would be sufficient for further investigation of alarm signs.
Colonoscopy has lower yield and correlation with symptoms in patients with constipation alone. Therefore, it is better not to use in patients with constipation and without any alarm sign.
Colonic function tests
Colonic manometry
Colonic manometry is 24-hour measurement of pressure within the large bowel, using specific probes and portable recorders.
The colon pressure is studied during different conditions, such as:[2]
Anorectal manometry during simulated defecation in left lateral decubitus position with inappropriate increase of rectal pressure (green color) and no decrease in anal sphincter pressure (yellow to red color) which is consistent with pelvic floor dyssynergia(A); and sitting position with rectal pressure increased (yellow to red color) in coordination with relaxation of the anal sphincter pressure (green color), which is a normal pattern of anorectal manometry(B), via https://openi.nlm.nih.gov
Balloon expulsion test is a simple bedside test to evaluate the ability of patient to evacuate the artificial stool.
The balloon filled with 50 cc of warm water or silicone-filled stool-like device is inserted into the rectum and the subject is asked to evacuate the balloon in sitting position. Expulsion within 1 minute is assumed as normal.[6]
Rectal barostat balloon-By No machine-readable author provided, via Wimimedia commons[8]
Rectal barotest test
Rectal biostat test consists of a very compliant plastic balloon, which is inserted into the rectum, concurrently connected to computer device to measure the pressure.
First, the balloon is inflated in the rectum and then the effect of various defecation maneuvers on the pressure will be recorded.
Decreased intrarectal pressure during the defecation is suggestive of constipation secondary to dyssynergism.[9]
References
↑Qureshi W, Adler DG, Davila RE, Egan J, Hirota WK, Jacobson BC, Leighton JA, Rajan E, Zuckerman MJ, Fanelli R, Wheeler-Harbaugh J, Baron TH, Faigel DO (2005). “ASGE guideline: guideline on the use of endoscopy in the management of constipation”. Gastrointest. Endosc. 62 (2): 199–201. doi:10.1016/j.gie.2005.04.016. PMID16046978.
↑Rao SS, Sadeghi P, Beaty J, Kavlock R, Ackerson K (2001). “Ambulatory 24-h colonic manometry in healthy humans”. Am. J. Physiol. Gastrointest. Liver Physiol. 280 (4): G629–39. doi:10.1152/ajpgi.2001.280.4.G629. PMID11254489.
↑Rao SS, Sadeghi P, Beaty J, Kavlock R (2004). “Ambulatory 24-hour colonic manometry in slow-transit constipation”. Am. J. Gastroenterol. 99 (12): 2405–16. doi:10.1111/j.1572-0241.2004.40453.x. PMID15571589.
↑Karlbom U, Lundin E, Graf W, Påhlman L (2004). “Anorectal physiology in relation to clinical subgroups of patients with severe constipation”. Colorectal Dis. 6 (5): 343–9. doi:10.1111/j.1463-1318.2004.00632.x. PMID15335368.
↑Rao SS, Mudipalli RS, Stessman M, Zimmerman B (2004). “Investigation of the utility of colorectal function tests and Rome II criteria in dyssynergic defecation (Anismus)”. Neurogastroenterol. Motil. 16 (5): 589–96. doi:10.1111/j.1365-2982.2004.00526.x. PMID15500515.
↑Rao SS, Hatfield R, Soffer E, Rao S, Beaty J, Conklin JL (1999). “Manometric tests of anorectal function in healthy adults”. Am. J. Gastroenterol. 94 (3): 773–83. doi:10.1111/j.1572-0241.1999.00950.x. PMID10086665.
↑Rao SS, Mudipalli RS, Stessman M, Zimmerman B (2004). “Investigation of the utility of colorectal function tests and Rome II criteria in dyssynergic defecation (Anismus)”. Neurogastroenterol. Motil. 16 (5): 589–96. doi:10.1111/j.1365-2982.2004.00526.x. PMID15500515.
