Disconnected pancreatic duct syndrome (DPDS) is a complex and challenging consequence of acute necrotizing pancreatitis, occurring when a segment of viable pancreatic tissue remains isolated from the main ductal system due to complete disruption of the pancreatic duct. This frequently leads to persistent fistulae or recurrent peripancreatic fluid collections and often requires tailored endoscopic or surgical management. However, intramural gastric involvement is exceedingly rare, and its optimal management is not yet well defined. We report the case of a 50-year-old male with a history of necrotizing hemorrhagic biliary pancreatitis, complicated by spleno-mesenteric venous thrombosis and a large walled-off necrosis. Endoscopic ultrasound-guided cystogastrostomy with placement of a lumen-apposing metal stent (LAMS) was performed, resulting in the initial drainage of the collection. The early postoperative course was complicated by peritonitis, successfully treated with laparoscopic washout. The LAMS was subsequently exchanged for a trans-gastric double pigtail stent. Months later, a follow-up MRI confirmed resolution of the main collections but demonstrated a disconnected pancreatic duct with mild upstream Wirsung dilatation, consistent with DPDS. The patient remained clinically stable for nearly one year with preserved pancreatic function. Then he presented with de novo recurrent nausea, vomiting, and epigastric discomfort without fever. Cross-sectional imaging (CT and MRI) revealed the cause: multiple circumferential intramural fluid collections within the gastric antrum, originating from the disconnected ductal segment and causing gastric outlet obstruction (GOO). The findings were consistent with an intramural extension of a persistent pancreatic fistula. Imaging confirmed the DPDS fistula was actively feeding these collections. Given the patient's complexity and absence of sepsis, a high-risk surgical or endoscopic bypass was deferred. Instead, a "step-down" conservative approach was chosen. As a key therapeutic step, the trans-gastric pigtail stent was removed, and the patient was managed with proton pump inhibitors, prokinetics, and dietary modifications. This approach led to a progressive clinical recovery, with restoration of normal alimentation and weight gain. Serial MRI demonstrated a marked reduction of the intramural collections and progressive involution of the fistulous tract. The patient maintained stable pancreatic and nutritional status. A multidisciplinary team recommended continued conservative management and delayed elective cholecystectomy once radiological stability was confirmed to prevent recurrence of biliary pancreatitis. This case illustrates a rare evolution of DPDS, where ductal leakage created intramural gastric collections, causing GOO. The stepwise combination of endoscopic techniques, radiologic monitoring, and patient-tailored conservative therapy enabled clinical and radiological resolution without the need for surgical bypass. This experience emphasizes the importance of long-term imaging surveillance and multidisciplinary coordination in the management of DPDS, as well as awareness that, in selected DPDS patients, vigilant surveillance and conservative management can be the optimal approach, even for severe complications.