一、定义 急性腹泻:排出大量稀便,持续不超过14天。 二、发病机制 引起急性腹泻的病因主要有以下几种:细菌、病毒、寄生虫以及非感染性疾病。通常认为腹泻是粪便中的水和电解质增加,以至于形成多次不成形粪便。肠壁的吸收和分泌失平衡导致了粪便中的水分增加。在肠内特别活跃的非侵袭性微生物可引起水性腹泻,这种腹泻不伴有发热,或仅伴有低热。这些微生物是通过与肠黏膜的相互作用引起腹泻的。具有肠毒性的大肠杆菌和霍乱弧菌在肠脏外不传播,它们并不侵袭肠上皮,但可增加肠毒素的产量,从而引起液体分泌而导致腹泻。一些微生物破坏肠道微绒毛的吸收表面,可引起双糖酶缺乏,如感染兰氏贾第鞭毛虫时可发生这种情况。还有一些侵袭性的微生物可穿透肠上皮而引起炎性紊乱,最常见于志贺菌感染。空肠弯曲菌和 First, the definition of acute diarrhea: excretion of loose stools, lasting no more than 14 days. Second, the pathogenesis The main causes of acute diarrhea are the following: bacteria, viruses, parasites and non-infectious diseases. Diarrhea is generally thought of as an increase in water and electrolytes in the feces, resulting in the formation of multiple, unformed fecal matter. The imbalance of absorption and secretion of the intestinal wall leads to an increase of water in the stool. Non-invasive microorganisms that are particularly active in the intestine can cause watery diarrhea that is not accompanied by fever or with fever only. These microbes cause diarrhea by interacting with intestinal mucosa. Enterotoxigenic E. coli and V. cholerae do not spread outside the gut. They do not invade the intestinal epithelium, but increase the production of enterotoxins, leading to the secretion of fluids leading to diarrhea. Some microorganisms destroy the intestinal microvilli’s absorbent surface and cause disaccharidase deficiency, as can happen with Giardia lamblia. There are also some invasive microorganisms that penetrate the intestinal epithelium and cause inflammatory disorders, most commonly Shigella infection. Campylobacter jejuni and