Ashraf W, Park F, Lof J, Quigley E M
Department of Internal Medicine, University of Nebraska Medical Center, Omaha 68198-2000, USA.
Am J Gastroenterol. 1996 Jan;91(1):26-32.
To investigate the reliability of reported stool frequency in the diagnosis of constipation.
Our criterion for the diagnosis of idiopathic constipation was < or = 3 stools per week for > or = 6 months. Subjects who believed that they met this criterion were invited to participate. Daily stool frequency was recorded over a 4-wk period, and all stools were weighed during the final week. A colon transit study and anorectal manometry were performed at the beginning and at the end of the study.
On review of stool diaries from 45 subjects who described chronic constipation and who completed the 4-wk study, only 22 (49%) actually satisfied our criterion for idiopathic constipation. The remaining 23 (51%) subjects, although describing constipation, had, on average, 6 stools/wk. A history of psychiatric illness was 5 times more frequent among those whose bowel symptoms correlated poorly with objective measures. Measures of difficult defecation were similar in the two groups. Mean colon transit time was significantly longer and correlated closely with stool weight only in subjects who truly were constipated (p < 0.05). Anorectal manometry was not helpful in discriminating between those who satisfied our criterion for constipation and those who did not.
Defining constipation on the basis of a patient's reported stool frequency may prove misleading; the diagnosis of idiopathic constipation should be supported by the use of stool diaries and a colon transit study.
研究报告的排便频率在便秘诊断中的可靠性。
我们诊断特发性便秘的标准是每周排便次数≤3次，且持续时间≥6个月。邀请自认为符合该标准的受试者参与研究。在4周的时间内记录每日排便频率，并在最后一周对所有粪便进行称重。在研究开始和结束时分别进行结肠运输试验和肛门直肠测压。
回顾45名自述患有慢性便秘且完成4周研究的受试者的排便日记，只有22名（49%）实际符合我们的特发性便秘标准。其余23名（51%）受试者虽然自述便秘，但平均每周排便6次。肠道症状与客观指标相关性较差的受试者中，精神疾病史的发生率高出5倍。两组的排便困难程度指标相似。仅在真正便秘的受试者中，平均结肠运输时间显著延长，且与粪便重量密切相关（p<0.05）。肛门直肠测压对区分符合我们便秘标准的受试者和不符合标准的受试者并无帮助。
基于患者报告的排便频率来定义便秘可能会产生误导；特发性便秘的诊断应通过排便日记和结肠运输试验来辅助。
