Wood Jackie D
Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Public Health, 1645 Neil Avenue, Columbus, OH 43210, USA.
J Clin Gastroenterol. 2007 May-Jun;41 Suppl 1:S7-19. doi: 10.1097/MCG.0b013e31802f1331.
A unified scenario emerges when it is considered that a major impact of stress on the intestinal tract is reflected by symptoms reminiscent of the diarrhea-predominant form of irritable bowel syndrome. Cramping abdominal pain, fecal urgency, and explosive watery diarrhea are hallmarks not only of diarrhea-predominant irritable bowel syndrome, but also of infectious enteritis, radiation-induced enteritis, and food allergy. The scenario starts with stress-induced compromise of the intestinal mucosal barrier and continues with microorganisms or other sensitizing agents crossing the barrier and being intercepted by enteric mast cells. Mast cells signal the presence of the agent to the enteric nervous system (ie, the brain-in-the-gut), which uses one of the specialized programs from its library of programs to remove the "threat." This is accomplished by stimulating mucosal secretion, which flushes the threatening agent into the lumen and maintains it in suspension. The secretory response then becomes linked to powerful propulsive motility, which propels the secretions together with the offending agent rapidly in the anal direction. Cramping abdominal pain accompanies the strong propulsive contractions. Urgency is experienced when arrival of the large bolus of liquid distends the recto-sigmoid region and reflexly opens the internal anal sphincter, with continence protection now provided only by central reflexes that contract the puborectalis and external anal sphincter muscles. Sensory information arriving in the brain from receptors in the rapidly distending recto-sigmoid accounts for the conscious sensation of urgency and might exacerbate the individual's emotional stress. The symptom of explosive watery diarrhea becomes self-explanatory in this scenario.
当我们考虑到压力对肠道的主要影响表现为类似腹泻型肠易激综合征的症状时，一个统一的情况就出现了。腹部绞痛、排便急迫感和爆发性水样腹泻不仅是腹泻型肠易激综合征的特征，也是感染性肠炎、放射性肠炎和食物过敏的特征。这种情况始于压力导致的肠道黏膜屏障受损，接着微生物或其他致敏剂穿过屏障并被肠道肥大细胞拦截。肥大细胞将该物质的存在信号传递给肠神经系统（即肠中之脑），肠神经系统从其程序库中调用一个专门程序来消除“威胁”。这是通过刺激黏膜分泌来实现的，黏膜分泌将威胁性物质冲入肠腔并使其保持悬浮状态。然后，分泌反应与强大的推进性蠕动相联系，推进性蠕动将分泌物与有害物质一起迅速向肛门方向推进。强烈的推进性收缩会伴有腹部绞痛。当大量液体到达使直肠乙状结肠区域扩张并反射性地打开肛门内括约肌时，就会出现排便急迫感，此时仅靠耻骨直肠肌和肛门外括约肌收缩的中枢反射来保护控便功能。从快速扩张的直肠乙状结肠中的感受器传入大脑的感觉信息解释了排便急迫感的自觉感受，并且可能会加剧个体的情绪压力。在这种情况下，爆发性水样腹泻的症状就不言自明了。
