Ng Clinton, Danta Mark, Kellow John, Badcock Caro-Anne, Hansen Ross, Malcolm Allison
Gastrointestinal Investigation Unit, Royal North Shore Hospital, University of Sydney, St Leonards, New South Wales, Australia.
Am J Physiol Gastrointest Liver Physiol. 2005 Sep;289(3):G489-94. doi: 10.1152/ajpgi.00527.2004. Epub 2005 May 19.
Alterations in normal intestinointestinal reflexes may be important contributors to the pathophysiology of irritable bowel syndrome (IBS). Our aims were to compare the rectal tonic responses to colonic distension in female IBS patients with predominant constipation (IBS-C) and with predominant diarrhea (IBS-D) to those in healthy females, both fasting and postprandially. Using a dual barostat assembly, 2-min colonic phasic distensions were performed during fasting and postprandially. Rectal tone was recorded before, during, and after the phasic distension. Colonic compliance and colonic sensitivity in response to the distension were also evaluated fasting and postprandially. Eight IBS-C patients, 8 IBS-D patients, and 8 age- and sex-matched healthy subjects (group N) participated. The fasting increments in rectal tone in response to colonic distension in both IBS-C (rectal balloon volume change -4.6 +/- 6.1 ml) and IBS-D (-7.9 +/- 4.9 ml) were significantly reduced compared with group N (-34 +/- 9.7 ml, P = 0.01). Similar findings were observed postprandially (P = 0.02). When adjusted for the colonic compliance of individual subjects, the degree of attenuation in the rectal tonic response in IBS compared with group N was maintained (fasting P = 0.007; postprandial P = 0.03). When adjusted for colonic sensitivity there was a trend for the attenuation in the rectal tonic response in IBS patients compared with group N to be maintained (fasting P = 0.07, postprandial P = 0.08). IBS patients display a definite attenuation of the normal increase in rectal tone in response to colonic distension (colorectal reflex), fasting and postprandially. Alterations in colonic compliance and sensitivity in IBS are not likely to contribute to such attenuation.
正常肠-肠反射的改变可能是肠易激综合征（IBS）病理生理学的重要促成因素。我们的目的是比较以便秘为主型（IBS-C）和腹泻为主型（IBS-D）的女性IBS患者与健康女性在空腹和餐后时直肠对结肠扩张的紧张性反应。使用双气囊压力测定装置，在空腹和餐后进行2分钟的结肠阶段性扩张。在阶段性扩张前、期间和之后记录直肠张力。还在空腹和餐后评估结肠对扩张的顺应性和敏感性。8名IBS-C患者、8名IBS-D患者和8名年龄及性别匹配的健康受试者（N组）参与研究。与N组（-34±9.7 ml，P = 0.01）相比，IBS-C组（直肠气囊容积变化-4.6±6.1 ml）和IBS-D组（-7.9±4.9 ml）在空腹时对结肠扩张的直肠张力增加均显著降低。餐后也观察到类似结果（P = 0.02）。当根据个体受试者的结肠顺应性进行调整时，IBS组与N组相比直肠紧张性反应的减弱程度得以维持（空腹时P = 0.007；餐后P = 0.03）。当根据结肠敏感性进行调整时，IBS患者与N组相比直肠紧张性反应减弱仍有维持趋势（空腹时P = 0.07，餐后P = 0.08）。IBS患者在空腹和餐后时，对结肠扩张（结直肠反射）的正常直肠张力增加明显减弱。IBS患者结肠顺应性和敏感性的改变不太可能导致这种减弱。
