Massive Gastrointestinal Hemorrhage in an Adult Caused by Meckel's Diverticulum: A Case Report.

Meckel's diverticulum is one of the most common congenital anomalies of the gastrointestinal tract in pediatric populations worldwide. Although Meckel's diverticulum itself is usually asymptomatic, patients often present with complications such as gastrointestinal bleeding, Meckel's diverticulitis, intestinal perforation, and other associated symptoms. Notably, Meckel's diverticulum is relatively uncommon in adults, with cases complicated by acute massive gastrointestinal bleeding being particularly rare. We report the case of a 41-year-old man presenting with hematochezia for one day. Upon admission, his hemoglobin level dropped significantly from 98 g/L to 62 g/L within 24 hours. Contrast-enhanced computed tomography strongly suggested contrast media extravasation, indicating active bleeding. Subsequent gastrointestinal endoscopy, including colonoscopy, failed to identify obvious pathological findings. Mesenteric angiography successfully localized the bleeding vessels, but multiple embolization attempts were unsuccessful. The initial imaging and endoscopic modalities may not pinpoint the source of bleeding in this rare condition. Ultimately, a combined laparoscopic and endoscopic approach was employed, which successfully identified and localized the bleeding site in the Meckel's diverticulum. Laparoscopic intestinal resection was then performed, and postoperative pathological examination confirmed Meckel's diverticulum with ectopic gastric tissue. Meckel's diverticulum-induced bleeding in adults is severe yet rare, with nonspecific diagnostic features that often complicate timely identification. In managing the case of massive gastrointestinal hemorrhage, we achieved a successful outcome through combined laparoscopic intestinal resection and endoscopic surgery, with timely diagnosis and targeted intervention leading to complete recovery. This case underscores the critical role of a multimodal diagnostic and therapeutic strategy, particularly the integration of laparoscopy and endoscopy, in overcoming the challenges of nonspecific presentations. It serves as a valuable reference for clinicians, emphasizing that persistent diagnostic uncertainty in severe lower gastrointestinal bleeding should prompt consideration of rare etiologies like Meckel's diverticulum, and that a combined surgical-endoscopic approach can be pivotal in achieving definitive diagnosis and curative treatment.