Constipation in critical care patients: both timing and duration matter

Most of the studies have defined constipation as a period without stool after ICU admission. We aimed to test the impact of both duration and timing of infrequent defecation in critical care patients.

We performed a prospective, bi-center, observational study. Patients were divided into three subgroups: 'not constipated', '3-5 days', and 'at least 6 days' (longest period without stool passage, respectively, shorter than 3 days, 3-5 days, and ≥6 days). Furthermore, 'early' constipated patients were defined as those for whom the longest time to stool passage occurred just after ICU admission, whereas for 'late' constipated patients the longest period without stool occurred later during ICU stay.

A total of 182 patients were included: the mean age was 67.2 years (54.4-78.9 years), 80 were women, and simplified acute physiology score II was 42 (34-52). In all, 42 (23.1%), 82 (45.1%), and 58 (31.8%) belonged to the nonconstipated, 3-5 days, or greater than or equal to 6 days subgroup of patients, respectively. Time spent under mechanical ventilation and ICU length of stay was longer in the greater than or equal to 6 days subgroups as compared with both other subgroups. ICU stay was longer in the 3-5 days subgroup as compared with the not constipated patients. Furthermore, the late patients of the greater than or equal to 6 days subgroups exhibited worse survival as compared with all other patients.

Both timing and duration of infrequent defecation seem to have an impact on critical care patient's outcome, and should therefore be included in the diagnostic criteria.