Figure 3. Colonic involvement by ERCP-induced pancreatitis due to retroperitoneal spread of inflammation in a 38-year-old woman. Multiple attempts were made to cannulate the pancreatic duct without success. The patient had postprocedure pain and an elevated amylase level with imaging evidence of acute pancreatitis. CT was performed with oral and intravenous contrast material 1 day after ERCP. CT scan shows inflammatory change (*) in the retroperitoneum abutting the ascending colon. The wall of the ascending colon is thickened (arrow) due to dissection of peripancreatic fluid and inflammation along the anterior pararenal space into the paracolic gutter to surround the cecum and ascending colon. The patient was treated with medical therapy, and follow-up CT performed 3 weeks later showed a decrease in colonic inflammation.