Endoscopic retrograde cholangiopancreatography (ERCP) is commonly used for biliary decompression in gallstone pancreatitis (GSP), but its optimal timing in uncomplicated GSP remains controversial. We evaluated outcomes of early versus delayed ERCP by disease severity.

We conducted a retrospective cohort study of 207 adults with GSP who underwent ERCP at a tertiary center (2019–2025). Patients were categorized as early (<48 h) or delayed (> 48 h). Outcomes included ERCP-related adverse events, pancreatitis-related complications, length of stay (LOS), intensive care unit (ICU) admission, and mortality. Continuous variables were analyzed using Welch’s t -test or Mann-Whitney U test, and categorical variables using chi-square or Fisher’s exact tests, with relative risks (RRs) and 95% confidence intervals.

Early (n = 103) and delayed (n = 104) groups were similar in demographics and Bedside Index of Severity in Acute Pancreatitis (BISAP) distribution, though delayed ERCP patients had higher Atlanta severity (15.4%vs 5.8%; p = 0.040). Early ERCP was associated with fewer ERCP-related complications (2.9%vs 17.3%; RR 0.17; p = 0.0008), less worsening pancreatitis (1.0%vs 12.5%; RR 0.08; p = 0.0013), fewer acute necrotic collections (0%vs 5.8%; p = 0.029), and lower ICU admission (8.7%vs 19.2%; p = 0.044). Among BISAP 0–1 patients, early ERCP reduced LOS by 2.17 days (p = 0.013). LOS differences in BISAP ≥2 patients were not significant. Mortality was low and did not differ significantly.

Early ERCP in GSP is associated with fewer complications, reduced ICU utilization, and shorter hospitalization in mild disease. These findings support early intervention in mild-to-moderate GSP and underscore the need for prospective multicenter studies.