Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.
Am J Gastroenterol. 2018 Jan;113(1):115-123. doi: 10.1038/ajg.2017.213. Epub 2017 Aug 1.
Our current understanding of normal bowel patterns in the United States (US) is limited. Available studies have included individuals with both normal and abnormal bowel patterns, making it difficult to characterize normal bowel patterns in the US. The current study aims to (1) examine frequency and consistency in individuals with self-reported normal bowel habits and (2) determine demographic factors associated with self-reported normalcy.
This study used data from adult participants who completed bowel health questions as part of the National Health and Nutrition Examination Survey (NHANES) in 2009-2010 and who reported normal bowel patterns (N=4,775). Data regarding self-perceived bowel health; stool frequency; stool consistency (using the Bristol Stool Form Scale (BSFS)); and demographic factors were analyzed.
95.9% of the sample reported between 3 and 21 BMs per week. Among men, 90% reported a BSFS between 3 and 5, while for women it was 2-6. After controlling for age, the following demographic variables were associated with normalcy: male sex, higher education, higher income, <2 daily medications, and high daily fiber intake. Hispanic ethnicity was significantly associated with abnormal self-reported bowel habits.
This is the first study to evaluate normal bowel frequency and consistency in a representative sample of adults in the US. The current findings bolster the common "3 and 3" metric of normal frequency (3 BMs/day to 3 BMs/week) while also suggesting different criteria for normal consistency for men and women. Finally, this study provides novel information about demographic factors associated with normal frequency and consistency.
我们目前对于美国正常排便模式的了解有限。现有的研究包括了排便模式正常和异常的个体，这使得我们难以确定美国的正常排便模式。本研究旨在：（1）检查自我报告正常排便习惯个体的频率和一致性；（2）确定与自我报告正常相关的人口统计学因素。
本研究使用了 2009-2010 年国家健康和营养检查调查（NHANES）中完成肠道健康问卷且报告正常排便模式的成年参与者的数据（N=4775）。分析了自我感知的肠道健康、排便频率、粪便稠度（使用布里斯托粪便量表（BSFS））以及人口统计学因素的数据。
样本中有 95.9%的人报告每周排便 3 到 21 次。在男性中，90%的人报告 BSFS 为 3-5，而女性为 2-6。在控制年龄后，以下人口统计学变量与正常性相关：男性、较高的教育程度、较高的收入、每日<2 种药物和高膳食纤维摄入量。西班牙裔与异常的自我报告肠道习惯显著相关。
这是第一项评估美国成年人代表性样本中正常排便频率和稠度的研究。目前的研究结果支持了常见的“3 和 3”正常频率（每日 3 次排便至每周 3 次排便），同时也为男性和女性的正常稠度提出了不同的标准。最后，本研究提供了与正常频率和稠度相关的人口统计学因素的新信息。
