Center for Functional GI and Motility Disorders, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
CSL Behring, King of Prussia, Pennsylvania, USA.
Am J Gastroenterol. 2014 Sep;109(9):1450-60. doi: 10.1038/ajg.2014.181. Epub 2014 Jul 1.
The objectives of this study were to determine whether the symptoms of diarrhea (defined as loose or watery stools), constipation (hard or lumpy stools), abdominal pain, and bloating occur in episodes rather than sporadically in patients with irritable bowel syndrome (IBS); to identify rules for defining the onset and termination of symptom episodes; and to assess the overlap of these episodes.
IBS patients kept a symptom log in which they rated the consistency of each bowel movement (BM) on the Bristol Stool Scale for 3 months. Each night they transferred these data to an internet website and also rated abdominal pain and bloating for that day. Data were analyzed for 124 patients who completed at least 21 consecutive diary days (mean of 73 days) without taking laxative, antidiarrheal, or IBS-specific medications. For each symptom in each patient, we computed the correlation between consecutive observations (autocorrelations) in the diary to determine whether the symptom tended to occur in clusters of several instances, as would happen in episodes vs. happening randomly. Next, we compared different patterns by which diarrhea and nondiarrhea stools alternate to identify episode definitions that captured at least 75% of loose/watery stools. A similar pattern analysis was performed for constipation. Pain and bloating episodes were defined as days with an intensity rating >3 on a 0-10 scale. These patterns were converted into rules for defining the onset and termination of symptom episodes. Last, we used these episode definitions to examine the overlap of pain with episodes of diarrhea, constipation, and pain.
Significant (P<0.05) autocorrelations were found in the Bristol Stool Scale ratings of 69.4% of patients and in the daily abdominal pain and bloating ratings of 52.4% and 68.5% of patients, respectively. Defining a diarrhea episode as two or more loose/watery stools never separated by >1 nonloose/watery stool or by a day without a BM captured 76% of all loose/water stools. Defining constipation episodes as two or more hard/lumpy stools never separated by >1 nonhard/lumpy stool captured 80% of hard/lumpy stools. Sequences of 3 or more days without a BM were also defined as constipation episodes because they were strongly associated with hard stools. Average episode durations were 2.1 days for diarrhea, 4.5 days for constipation, 3.1 days for pain, and 3.5 days for bloating. Overlap analysis showed that only 41.6% of constipation episode days and 67.0% of diarrhea episode days were pain episode days. Bloating and pain coexisted on 59.1% of days on which either type occurred.
Loose/watery stools and hard/lumpy stools occur in well-defined episodes. Pain and bloating also occur in episodes, but contrary to the Rome criteria more than half of the pain episodes occur outside episodes of abnormal stool consistency.
本研究旨在确定肠易激综合征（IBS）患者的腹泻（定义为稀便或水样便）、便秘（硬便或块状便）、腹痛和腹胀症状是否呈发作性而非散在发生；确定发作性症状的起始和终止的规则；评估这些发作之间的重叠。
IBS 患者记录症状日志，记录 3 个月内每天的大便稠度（Bristol 粪便量表）。每晚他们将这些数据转移到互联网网站，并对当天的腹痛和腹胀进行评分。对至少完成 21 天连续日记（平均 73 天）且未服用泻药、止泻药或 IBS 特异性药物的 124 名患者进行数据分析。对于每个患者的每种症状，我们计算日记中连续观察之间的相关性（自相关），以确定该症状是否倾向于以多个实例的簇发生，就像在发作中发生的那样，而不是随机发生。接下来，我们比较不同的交替模式，以确定腹泻和非腹泻粪便之间的交替，以确定至少捕获 75%稀便/水样便的发作定义。对便秘也进行了类似的模式分析。疼痛和腹胀发作定义为强度评分为 0-10 分的 1 天>3 分。将这些模式转换为定义症状发作起始和终止的规则。最后，我们使用这些发作定义来检查疼痛与腹泻、便秘和疼痛发作之间的重叠。
69.4%的患者Bristol 粪便量表评分、52.4%和 68.5%的患者每日腹痛和腹胀评分存在显著（P<0.05）的自相关。将腹泻发作定义为两次或两次以上的稀便/水样便，且其间从未有一次非稀便/水样便或无粪便，则可捕获所有稀便/水样便的 76%。将便秘发作定义为两次或两次以上的硬便/块状便，且其间从未有一次非硬便/块状便，可捕获 80%的硬便/块状便。没有粪便的 3 天或更长时间的序列也被定义为便秘发作，因为它们与硬便强烈相关。腹泻发作的平均持续时间为 2.1 天，便秘发作的平均持续时间为 4.5 天，腹痛发作的平均持续时间为 3.1 天，腹胀发作的平均持续时间为 3.5 天。重叠分析表明，只有 41.6%的便秘发作天数和 67.0%的腹泻发作天数是疼痛发作天数。在出现异常粪便稠度的日子里，有 59.1%的日子会同时出现腹胀和疼痛。
稀便/水样便和硬便/块状便呈明确的发作性发生。疼痛和腹胀也呈发作性发生，但与罗马标准不同，超过一半的疼痛发作发生在异常粪便稠度的发作之外。
