Comparison of Straining During Defecation in Three Positions: Results and Implications for Human Health


The aim of the study was to compare the straining forces applied when sitting or squatting during defecation. Twenty-eight apparently healthy volunteers (ages 17–66 years) with normal bowel function were asked to use a digital timer to record the net time needed for sensation of satisfactory emptying while defecating in three alternative positions: sitting on a standard-sized toilet seat (41–42 cm high), sitting on a lower toilet seat (31–32 cm high), and squatting. They were also asked to note their subjective impression of the intensity of the defecation effort. Six consecutive bowel movements were recorded in each position. Both the time needed for sensation of satisfactory bowel emptying and the degree of subjectively assessed straining in the squatting position were reduced sharply in all volunteers compared with both sitting positions (P < 0.0001). In conclusion, the present study confirmed that sensation of satisfactory bowel emptying in sitting defecation posture necessitates excessive expulsive effort compared to the squatting posture.

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  1. 1.

    Gatewood WE: The mechanics of the colon. Northwest Med 29:1-7, 1930

  2. 2.

    Connel AM, Hilton C, Irvine G, Lennard-Jones JE, Misiewicz JJ: Variation of bowel habit in two population samples. Br Med J 2:1095-1099, 1965

  3. 3.

    Shorvon PJ, Mchugh S, Diamant NE, Somers S, Stevenson GW: Defecography in normal volunteers: results and implications. Gut 30:1737-1749, 1989

  4. 4.

    Altomare DF, Rinaldi M, Veglia A, Guglielmi A, Sallustio PL, Tripoli G: Contribution of posture to the maintenance of anal continence Int J Colorectal Dis 16:51-54, 2001

  5. 5.

    Tagart RE: The anal canal and rectum: their varying relationship and its effect on anal continence. Dis Colon Rectum 9:449-452, 1966

  6. 6.

    Timoshenko S: Theory of Elastic Stability. New York, McGraw-Hill, 1936

  7. 7.

    Haubruch W: Constipation. In Bockus Gastroenterology, 4th ed. J Berk (ed). Philadelphia, Saunders, 1985, p 111

  8. 8.

    Boles R: Constipation. JAMA 89:1766-1770, 1927

  9. 9.

    Singer C, Holmyard E, Hall A, Williams T: History of Technology. The Industrial Revolution 1750–1850, Oxford, Clarendon Press, 1958, pp 507-508

  10. 10.

    Burkitt D, Walker A, Painter N: Dietary fiber and disease. JAMA 229:1068-1074, 1974

  11. 11.

    Eastwood M, Smith A, Brydon W, Pritchard J: Colonic function in patients with diverticular disease. Lancet 1:1181-1182, 1978

  12. 12.

    Parks T, Connel A: Motility studies in diverticular disease of the colon. Gut 10:534-542, 1969

  13. 13.

    Weinreich J, Andersen D: Intraluminal pressure in the sigmoid colon. Patients with sigmoid diverticula and related conditions. Scand J Gastroenterol 11:581-586, 1976

  14. 14.

    McGuire J, Green RS, Haenstein V, Courter S, Braunstein JR, Plessinger V, Iglauer A, Noertker J: Bed pan deaths. Am Pract Dig Treatment 1:23-28, 1950

  15. 15.

    Schartum S: Ventricular arrest caused by the Valsalva maneuver in a patient with Adams-Stokes attacks accompanying defecation. Acta Med Scand 184:65-68, 1968

  16. 16.

    Benchimal A., Wang FU, Desser KB, Gartlan JL: The Valsalva maneuver and coronary arterial blood flow velocity. Ann Intern Med 77:357-360, 1972

  17. 17.

    Greenfield J: Transient changes in cerebral vascular resistance during the Valsalva maneuver in man. Stroke 15:76-79, 1984

  18. 18.

    Kapoor, W. N, Peterson J, Karpf M: Defecation syncope. Arch Intern Med 146:2377-2379, 1986

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Sikirov, D. Comparison of Straining During Defecation in Three Positions: Results and Implications for Human Health. Dig Dis Sci 48, 1201–1205 (2003).

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  • straining
  • sitting
  • squatting
  • defecation posture