Objective:To investigate the value of evaluating pancreatic exocrine insufficiency with fecal pancreatic elastase-1 in the clinical staging of chronic pancreatitis and prognosis evaluation.Methods:A total of 100 patients with pancreatic exocrine insufficiency (patient group) who received treatment in Wenzhou Central Hospital from January 2021 to June 2022 and 100 subjects without pancreatic exocrine insufficiency (control group) were included in this study. Fecal pancreatic elastase-1 content was measured by an enzyme linked immunosorbent assay. The receiver operating characteristic (ROC) curve was plotted to evaluate the value of fecal pancreatic elastase-1 content in the diagnosis of pancreatic exocrine insufficiency. Fecal pancreatic elastase-1 content was compared among patients with different clinical stages of chronic pancreatitis. The factors that affect the prognosis of patients with chronic pancreatitis were analyzed using logistic regression analysis.Results:Pancreatic elastase-1 content in the patient group was (63.28 ± 13.24) μg/g, which was significantly lower than (768.29 ± 102.59) μg/g in the control group ( t = 68.16, P < 0.05). The sensitivity, specificity, Youden index, and 95% CI of using pancreatic elastase-1 content to diagnose pancreatic exocrine insufficiency were 74.7%, 63.5%, 0.724, and 0.740-0.870, respectively. Among the 200 included subjects, 103 had chronic pancreatitis. With the increase in M-ANNHEIM clinical stage, fecal pancreatic elastase-1 content in patients with chronic pancreatitis gradually decreased ( F = 182.66, P < 0.05). Pancreatic elastase-1 content < 200 μg/g was used as a standard to evaluate pancreatic exocrine function. Results showed that 35 patients had stage I chronic pancreatitis, 40 patients had stage II chronic pancreatitis, and 28 patients had stage III chronic pancreatitis. There was no significant difference in the number of patients with different stages of chronic pancreatitis between the two clinical stage classification methods ( χ2 = 12.46, P = 0.002). Six-month follow-up results showed that among 103 patients with chronic pancreatitis, 31 had a poor prognosis (30.1%). Univariate analysis revealed that there were significant differences in age at onset, body mass index, triglyceride level, alcohol consumption, and pancreatic elastase-1 content among patients with different prognoses ( χ2 = 24.07, 4.27, 5.43, 8.38, 4.93, P < 0.05). Multivariate logistic regression analysis showed that age at onset, body mass index, triglyceride level, alcohol consumption, and pancreatic elastase-1 content were the independent influential factors of prognosis in patients with chronic pancreatitis [ OR (95% CI) = 4.207 (2.741-11.609), 1.870 (1.241-2.972), 1.984 (1.437-3.113), 2.769 (1.827-5.125), 1.951 (1.469-3.387), all P < 0.05]. Conclusion:Pancreatic elastase-1 content is of great value in assessing pancreatic exocrine insufficiency, and is closely related to the clinical staging and prognosis of patients with chronic pancreatitis. Therefore, fecal pancreatic elastase-1 content is expected to be a reliable reference for assessing the progress of chronic pancreatitis and predicting its prognosis.