选取解放军总医院第二医学中心564例拟行结肠镜检查老年患者，随机分为硫酸镁溶液分次口服组和单次口服组，比较两组患者一般资料、肠道准备完成情况、病变检出率、不良反应发生率、满意度及检查后血电解质异常情况等。

两组病例在年龄、性别、体重指数(BMI)等无明显差别；分次组肠道准备波士顿总评分为(8.01±0.67)，优于单次组(7.35±0.58)，差异具有统计学意义(P<0.05)；分次组肠道息肉及微小息肉(直径<0.5 cm)检出率分别为103/282(36.5%)及81/282(28.7%)，较单次组87/282(30.9%)及64/282(22.7%)增高，差异均具有统计学意义(均P<0.05)。分次组有15例出现腹胀不适症状、3例出现腹痛、13例发生恶心、2例出现呕吐、5例因肠道准备不充分需要进一步补充灌肠。单次组则有36例出现腹胀不适、5例出现腹痛、27例发生恶心、7例出现呕吐、16例因肠道准备不充分需要进一步补充灌肠。分次组肠道准备满意率达97.9%，高于单次组(90.4%)，差异具有统计学意义(P<0.05)。两组检查后血钠、血钾、血镁及血钙的紊乱发生率均较低，且在两组间无明显差异(均P>0.05)。

硫酸镁溶液分次口服法较单次口服法肠道准备效果好，不良反应发生率更低，对血电解质并无明显影响，适合在老年人群中应用。

To evaluate the efficacy and safety of different oral methods of Magnesium sulfate solution for bowel preparation before colonoscopy in elderly patients and its influence on blood electrolytes.

A total of 564 elderly patients undergoing colonoscopy in the second medical center of PLA General Hospital were randomly divided into two groups: magnesium sulfate solution in split dose group and in single douse group. The general information, bowel preparation, lesion detection rate, incidence of adverse reactions, satisfaction and abnormal changes of blood electrolyte were compared between the two groups.

There was no significant difference in age, gender, body mass index (BMI) between the two groups; The total score for Boston bowel preparation in the split dose group was (8.01 ± 0.67), which was better than that in the single dose group (7.35 ± 0.58), and the difference was statistically significant (P< 0.05); the detection rates of intestinal polyps and micro polyps (diameter < 0.5 cm) in the split dose group were 103/282 (36.5%) and 81/282 (28.7%), which were higher than 87/282 (30.9%) and 64/282 (22.7%) in the single dose group, the differences were statistically significant (both P< 0.05). There were 15 cases of abdominal distension, 3 cases of abdominal pain, 13 cases of nausea and 2 cases of vomiting in the split dose group, and 5 cases needed further enema due to inadequate bowel preparation. In the single dose group, 36 cases had abdominal distension, 5 cases had abdominal pain, 27 cases had nausea, 7 cases had vomiting, and 16 cases needed further enema due to inadequate bowel preparation. The satisfaction rate of bowel preparation in the split dose group was 97.9%, which was higher than that in the single group (90.4%), and the difference was statistically significant (P< 0.05). The incidence of electrolyte abnormality was lower in both groups, and there was no significant difference between the two groups (P> 0.05).

Compared with single oral administration, magnesium sulfate solution oral in split dose has better bowel preparation effect, lower incidence of adverse reactions and no significant effect on blood electrolytes, so it is suitable for elderly patient.