正常人大便在每日２～３次或每周２～３次不等。大便的重量一般在每日１５０～２００ｇ之间 ,其中含有的水分在６０ %～８０%。腹泻则是指排便次数增多 ,每日超过３次以上 ,排粪便的量增多每日超过２００ｇ,粪质稀薄含有水分超过８５ %。慢性腹泻是指持续腹泻超过３～６周或者 Normal stool in the daily 2 to 3 times or 2 to 3 times a week range. The weight of the stool is usually between 150 ~ 200g per day, which contains 60% ~ 80% moisture. Diarrhea refers to the increase in the number of bowel movements, more than 3 times daily, the amount of defecation increased more than 200g daily, fecal thin water contains more than 85%. Chronic diarrhea means more than 3 to 6 weeks of persistent diarrhea or