Delayed return of bowel function after general surgery in South Australia.

Introduction: Reference ranges for determining pathological versus normal postoperative return of bowel function are not well characterised for general surgery patients. This study aimed to characterise time to first postoperative passage of stool after general surgery; determine associations between clinical factors and delayed time to first postoperative stool; and evaluate the association between delay to first postoperative stool and prolonged length of hospital stay.

Methods: This study included consecutive admissions at two tertiary hospitals across a two-year period whom underwent a range of general surgery operations. Multivariable logistic regression analyses were conducted to determine associations between the explanatory variables and delayed first postoperative stool, and between delayed first postoperative stool and length of hospital stay. The previously specified explanatory variables were used, with the addition of the dichotomised ≥4-day delay to first postoperative stool. Prolonged length of hospital stay was considered ≥7 days.

Results: 2,212 general surgery patients were included. Median time to first postoperative stool was 2.28 (IQR 1.06-3.96). Median length of stay was 7.19 (IQR 4.50-12.01). Several operative characteristics and medication exposures were associated with delayed first postoperative stool. There was a statistically significant association between delayed first postoperative stool (≥4 days) and prolonged length of stay (≥7 days) (OR 4.34, 95 %CI 3.27 to 5.77,  < 0.001).

Conclusions: This study characterised expected reference ranges for time to return of bowel function across various general surgery operations and determined associations with clinical factors that may improve efficiency and identification of pathology within the postoperative course.