Division of Gastroenterology, Mayo Clinic College of Medicine, Rochester, MN, USA.
Dig Liver Dis. 2009 Nov;41(11):772-80. doi: 10.1016/j.dld.2009.07.005. Epub 2009 Aug 8.
Symptoms consistent with the irritable bowel syndrome are remarkably frequent around the world. Irritable bowel syndrome prevalence ranges from 2.1% to 22%, depending on criteria used. Women are more frequently affected than men, but the reasons remain obscure; irritable bowel syndrome occurs in all age groups but there appears to be a modest decline in prevalence with advancing age again for unknown reasons. The incidence of irritable bowel syndrome per year has been estimated at approximately 1.5% in community subjects; annually only 0.2% of population will be diagnosed with irritable bowel syndrome. The natural history of irritable bowel syndrome is characterized by symptomatic flare ups and by a high rate of transition to other functional gastrointestinal diseases over the long term. Well recognized risk factors for irritable bowel syndrome include psychological distress and gastroenteritis. However, the association of psychological distress in some cases may reflect confounding factors and might be explained at least in part by cytokine production. Familial aggregation of irritable bowel syndrome occurs, and while the environment is key, twin studies generally support a genetic component in irritable bowel syndrome explaining up to 20% of the variability. Prior surgery may increase risk of irritable bowel syndrome. Early childhood trauma may be important; a low birth weight, nasogastric suction at birth, childhood abuse, and low socioeconomic status may carry an increased risk of suffering with irritable bowel syndrome as an adult. The role of diet remains uncertain but under-studied.
世界各地频繁出现符合肠易激综合征症状的病例。肠易激综合征的患病率因采用的标准不同而在 2.1%至 22%之间波动。女性比男性更容易受影响，但原因尚不清楚；肠易激综合征可见于所有年龄段，但由于未知原因，随着年龄的增长，其患病率似乎略有下降。每年社区人群中肠易激综合征的发病率约为 1.5%；每年仅有 0.2%的人群会被诊断为肠易激综合征。肠易激综合征的自然病程以症状发作和长期向其他功能性胃肠道疾病转变的高发生率为特征。公认的肠易激综合征危险因素包括心理困扰和胃肠炎。然而，在某些情况下心理困扰的关联可能反映了混杂因素，至少部分可以通过细胞因子的产生来解释。肠易激综合征存在家族聚集性，尽管环境是关键，但双胞胎研究普遍支持肠易激综合征存在遗传成分，可解释其 20%的变异性。先前的手术可能会增加肠易激综合征的风险。儿童早期创伤可能很重要；出生时低体重、鼻胃抽吸、儿童期虐待和低社会经济地位可能会增加成年后患肠易激综合征的风险。饮食的作用仍然不确定，但研究不足。
