Constipation, diarrhea, and prophylactic laxative bowel regimens in the critically ill: A systematic review and meta-analysis

Introduction: Prophylactic laxative bowel regimens may prevent constipation in enterally-fed critically ill patients. However, their use may also increase diarrhea. We performed a systematic review to: 1. Explore the epidemiology of constipation and/or diarrhea in critically ill patients; and 2. Appraise trials evaluating prophylactic laxative bowel regimens. Methods: We searched MEDLINE, Embase, and CINAHL for publications that reported constipation or diarrhea in critically ill adult patients and/or prophylactic laxative bowel regimens. Results: The proportion of critically ill patients experiencing constipation was reported between 20% and 83% and the proportion experiencing diarrhea was reported between 3.3% and 78%. Six studies of prophylactic laxative bowel regimens were identified but only 3 randomised controlled trials were identified, and these were subjected to meta-analysis. Compared with placebo, a prophylactic laxative bowel regimen increased the risk of diarrhea (RR 1.58, 95% CI 1.22 to 2.04) but did not reduce the risk of constipation (RR 0.39, 95% CI 0.14 to 1.05), and did not affect the duration of mechanical ventilation, duration of ICU admission, or mortality. Conclusions: Constipation and diarrhea occur frequently in the critically ill but data evaluating prophylactic laxative bowel regimens in such patients are sparse and do not support their use.