Purpose: To study the incidence, predictors, and outcomes of diarrhea during the stay in the intensive care unit (ICU). Methods: Prospective cohort of consecutive adults in the ICU for > 24 h during a 10-week period across 12 intensive care units (ICUs) internationally. The explored outcomes were: (1) incidence of diarrhea, (2) Clostridioides difficile-associated diarrhea (CDAD); (3) ICU and hospital length of stay (LOS) and mortality in patients with diarrhea. We fit generalized linear models to evaluate the predictors, management, morbidity and mortality associated with diarrhea. Results: Among 1109 patients aged 61.4 (17.5) [mean (standard deviation)] years, 981(88.5%) were medical and 645 (58.2%) were mechanically ventilated. The incidence was 73.8% (818 patients, 73.8%, 95% confidence interval [CI] 71.1–76.6) using the definition of the World Health Organisation (WHO). Incidence varied across definitions (Bristol 53.5%, 95% CI 50.4–56.7; Bliss 37.7%, 95% CI 34.9–40.4). Of 99 patients with diarrhea undergoing CDAD testing, 23 tested positive (2.2% incidence, 95% CI 1.5–3.4). Independent predictors included enteral nutrition (RR 1.23, 95% CI 1.16–1.31, p < 0.001), antibiotic days (RR 1.02, 95% CI 1.02–1.03, p < 0.001), and suppositories (RR 1.14 95% CI 1.06–1.22, p < 0.001). Opiates decreased diarrhea risk (RR 0.76, 95% CI 0.68–0.86, p < 0.001). Diarrhea prompted management modifications (altered enteral nutrition or medications: RR 10.25, 95% CI 5.14–20.45, p < 0.001) or other consequences (fecal management device or CDAD testing: RR 6.16, 95% CI 3.4–11.17, p < 0.001). Diarrhea was associated with a longer time to discharge for ICU or hospital stay, but was not associated with hospital mortality. Conclusion: Diarrhea is common, has several predictors, and prompts changes in patient care, is associated with longer time to discharge but not mortality.
