目的研究小儿腹泻病继发乳糖不耐受的年龄、病因及乳糖酶治疗继发乳糖不耐受的效果。方法对382例腹泻继发乳糖不耐受患儿进行年龄、病因分析,同时将患儿分成治疗及对照两组,分析乳糖酶的疗效。结果小儿腹泻继发乳糖不耐受以婴幼儿多见,轮状病毒感染是继发乳糖不耐受的主要病因,乳糖酶治疗继发乳糖不耐受疗效显著。结论婴幼儿腹泻常规给予乳糖酶可以缩短病程,减少治疗费用,患儿及家长易于接受。 Objective To study the age and etiology of secondary lactose intolerance in children with diarrhea and the effect of lactase in secondary lactose intolerance. Methods The age and etiology of 382 cases of secondary lactose intolerance in children with diarrhea were analyzed. At the same time, the children were divided into treatment and control groups, and the efficacy of lactase was analyzed. Results Infantile diarrhea secondary to lactose intolerance more common in infants and young children, rotavirus infection is the leading cause of secondary lactose intolerance, lactase secondary lactose intolerance significant effect. Conclusion The routine administration of lactase to infantile diarrhea can shorten the course of the disease and reduce the cost of treatment, which is easily accepted by children and parents.