[Study on the application of oral magnesium sulfate solution in split doses as bowel preparation for colonoscopy in elderly patients]

Objective: To evaluate the efficacy and safety of oral magnesium sulfate solution in split doses as bowel preparation in elderly patients undergoing colonoscopy. Methods: A total of 368 elderly patients undergoing colonoscopy were enrolled at PLA General Hospital. The patients were randomly divided into magnesium sulfate solution orally in split doses group (group A, n=178) and single dose group (group B, n=190). Parameters including general information, defecation frequency, Boston bowel preparation score (BBPS), detection rate of lesions and adverse reactions. Results: The frequency of defecations in group A was (7.6±1.4), more than that in group B (6.6±1.5) with statistical significance (P0.05). The duration of bowel preparation in group A was (128.6±25.3) min, shorter than that of group B (165.4±29.7) min (P0.05). The BBPS in group A was (8.09±0.67), better than that of group B (7.34±0.58) (P0.05). The detection rates of intestinal polyps and micropolyps (diameter0.5 cm) in group A were 73/178 (41.0%) and 51/178 (28.7%) respectively, compared with 58/190 (30.5%) and 37/190 (19.5%) in group B (both P0.05). In group A, 8 patients reported adverse reactions as abdominal distension and discomfort. One patient had ST-T abnormality of electrocardiogram (ECG). No nausea or vomiting occurred, yet 2 cases needed enema for inadequate bowel preparation. Twenty-one cases in group B reported adverse events including 7 with nausea and vomiting. There were 13 patients treated with enema. Abnormal ECG was found in 4 patients in group B. The satisfaction rate of group A was 97.8%, higher than that of group B (91.6%) (P0.05). Conclusions: The effect of bowel preparation of elderly patients with magnesium sulfate solution in split dose has a better tolerance, good cleaning effect and low incidence of adverse reactions. It is an ideal choice for the elderly to prepare colonoscopy.