在美国,肠易激综合征发生于 10% 至 15% 的成年人中。[4]Peery AF, Dellon ES, Lund J, et al. Burden of gastrointestinal disease in the United States: 2012 update. Gastroenterology. 2012 Aug 8;143(5):1179-87.e3.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3480553/http://www.ncbi.nlm.nih.gov/pubmed/22885331?tool=bestpractice.com 一项在保健组织成员中进行的调查显示,在回应人群中IBS症状存在比例达到19.5%。[5]Longstreth GF, Wolde-Tsadik G. Irritable bowel syndrome type symptoms in HMO examinees. Prevalence, demographics, and clinical correlates. Dig Dis Sci. 1993 Sep;38(9):1581-9.http://www.ncbi.nlm.nih.gov/pubmed/8359067?tool=bestpractice.com 欧洲肠易激综合征的患病率与此类似,并且虽然可能低于亚太地区,但其患病率正在上升。[6]World Gastroenterology Organisation. Irritable bowel syndrome: a global perspective. 2015 [internet publication].http://www.spg.pt/wp-content/uploads/2015/11/2015-IBS.pdf 关于非洲患病率的报告各不相同,但有报告称患病率可高达 33%。[6]World Gastroenterology Organisation. Irritable bowel syndrome: a global perspective. 2015 [internet publication].http://www.spg.pt/wp-content/uploads/2015/11/2015-IBS.pdf 在英国,据估计总患病率为 17%,但女性的患病率 (23%) 高于男性 (11%)。[7]Ford AC, Talley NJ. Irritable bowel syndrome. BMJ. 2012 Sep 4;345:e5836.http://www.ncbi.nlm.nih.gov/pubmed/22951548?tool=bestpractice.com[8]Chey WD, Maneerattaporn M, Saad R. Pharmacologic and complementary and alternative medicine therapies for irritable bowel syndrome. Gut Liver. 2011 Sep;5(3):253-66.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166664/http://www.ncbi.nlm.nih.gov/pubmed/21927652?tool=bestpractice.com
在澳大利亚,一项通讯问卷调查(4500人参加,年龄≥18岁)提示,根据曼宁(Manning)标准、罗马I和罗马II标准,IBS患病率分别为13.6%,6.9%和4.4%。[9]Boyce PM, Koloski NA, Taley NJ. Irritable bowel syndrome according to varying diagnostic criteria: are the new Rome II criteria unnecessarily restrictive for research and practice? Am J Gastroenterol. 2000 Nov;95(11):3176-83. Erratum in Am J Gastroenterol. 2001 Apr;96(4):1319. 在亚洲,类似的问卷调查揭示了相似但偏低的IBS患病率。在新加坡,根据曼宁(Manning)标准(符合>1条标准)、罗马I和罗马II标准,患病率分别为11.0%、10.4%和8.6%;在中国,根据曼宁(Manning)标准和改良罗马II标准,患病率分别为11.5%和5.7%,女性表现出更高的患病率。[10]Gwee KA, Wee S, Wong ML, et al. The prevalence, symptom characteristics, and impact of irritable bowel syndrome in an Asian urban community. Am J Gastroenterol. 2004 May;99(5):924-31. 在前来寻求医疗帮助的人群中,女性人数超过男性人数,二者比例为 2:1。[11]Saito YA, Schoenfeld P, Locke GR 3rd. The epidemiology of irritable bowel syndrome in North America: a systematic review. Am J Gastroenterol. 2002 Aug;97(8):1910-5.http://www.ncbi.nlm.nih.gov/pubmed/12190153?tool=bestpractice.com 目前对于此疾病患病率的趋势变化尚无数据。 32%~44%的患者都曾报告遭遇过躯体或性虐待史。[12]Walker EA, Katon WJ, Roy-Byrne PP, et al. Histories of sexual victimization in patients with irritable bowel syndrome or inflammatory bowel disease. Am J Psychiatry. 1993 Oct;150(10):1502-6.http://www.ncbi.nlm.nih.gov/pubmed/8379554?tool=bestpractice.com IBS症状也可在肠道感染后出现。[2]Longstreth GF, Thompson WG, Chey WD, et al. Functional bowel disorders. Gastroenterology. 2006 Apr;130(5):1480-91.http://www.gastrojournal.org/article/S0016-5085(06)00512-9/fulltexthttp://www.ncbi.nlm.nih.gov/pubmed/16678561?tool=bestpractice.com IBS 可见于青少年及各成人年龄组。一项研究发现亚洲儿童和青少年的患病率变化范围为 2.8% 至 25.7%,女性患病率略高于男性。[13]Devanarayana NM, Rajindrajith S, Pathmeswaran A, et al. Epidemiology of irritable bowel syndrome in children and adolescents in Asia. J Pediatr Gastroenterol Nutr. 2015 Jun;60(6):792-8.http://www.ncbi.nlm.nih.gov/pubmed/26000888?tool=bestpractice.com 50岁以上才开始出现症状很少见。