Lower gastrointestinal bleeding (LGIB) is a common emergency, defined nowadays as bleeding of colorectal origin. It predominantly affects elderly patients in whom it is associated with increased morbidity and mortality. The main causes include diverticulosis, anorectal disorders, angiodysplasias, ischemic colitis, post-endoscopic resection complications, and tumor-related bleeding. Clinically, lower gastrointestinal bleeding (LGIB) presents with episodes of hematochezia or melena, or sometimes as occult bleeding. Initial assessment of clinico-biological severity and risk of recurrence is essential to determine the need for hospitalization and the timing of diagnostic procedures. Colonoscopy is the reference diagnostic and therapeutic procedure, ideally performed within 24 hours with CT angiography reserved for cases of hemodynamic instability. In case of failure, therapeutic escalation includes repeat endoscopy, arterial embolization, and, as a last resort, surgery. Early multidisciplinary management helps reduce morbidity, mortality, and recurrence.

Non-portal hypertension-related upper gastrointestinal bleeding (UGIB) remains one of the most common emergencies in gastroenterology, accounting for the majority of UGIB cases in Western countries.Its incidence is estimated at 50-150 cases per 100.000 population per year, with a mortality rate that remains between 5% and 10% despite advances in diagnostic and therapeutic strategies. Clinical presentation is often abrupt, typically as hematemesis or melena, requiring prompt and structured management including initial resuscitation, diagnostic and therapeutic endoscopy, and secondary prevention.In recent years, the therapeutic armamentarium available to the endoscopist has expanded with the introduction of innovative devices such as over-the-scope clips, hemostatic powders, and gels. Several randomized trials have refined the optimal timing of endoscopy and compared the efficacy of various techniques.

Gastrointestinal bleeding (GIB) is a frequent and potentially life-threatening emergency. It is defined as any bleeding originating from the digestive tract, either overt (hematemesis, hematochezia, melena) or occult. From a nosological perspective, GIB is classified into upper GIB (proximal to the Treitz ligament), lower GIB (colonic or anorectal origin), suspected small bowel bleeding (SSBB), mid-GIB (jejunal or ileal lesions), and obscure GIB (no source identified despite complete evaluation). Over the past 20 years, the incidence of upper GIB has declined by 30-50%, mainly due to Helicobacter pylori eradication, proton pump inhibitors use, and reduced tobacco consumption. Conversely, lower GIB is increasing, and in some countries has surpassed upper GIB in frequency. Hospital mortality has decreased from about 10% to 5-7% owing to advances in diagnostics, therapeutic endoscopy, and healthcare organization. Cirrhotic patients and the elderly remain at particularly high risk.

This report describes a 25-year-old, intact male brown bear (Ursus arctos) presenting with weight loss, diarrhea, melena, apathy, and a 12% hematocrit. Ultrasound showed proximal duodenal wall thickening with submucosal cysts and a large, heterogeneous, highly vascularized mass in the descending duodenum, containing small gas pockets and compressing the lumen. The pancreas was visualized at the beginning of the descending duodenum, with normal echogenicity and slightly heterogeneous echotexture, containing a large cyst. Upper gastrointestinal endoscopy revealed bleeding and a partially obstructive duodenal mass with abundant fresh blood. A few days later, the animal died from hemorrhage as there were no possibilities for transfusion and consequently surgery. Histopathology revealed well-differentiated exocrine pancreatic adenocarcinoma infiltrating the duodenum. According to the scarce literature found, the ultrasonographic and endoscopic appearance of pancreatic adenocarcinoma in a brown bear has never been described.

A 10.5-year-old male castrated Standard Poodle was referred for the evaluation of chronic C6-T2 myelopathy. MRI revealed a severe asymmetric enlargement of the ventral internal vertebral venous plexus, intervertebral/vertebral veins, and possibly the C6 basivertebral vein, with secondary mild spinal cord compression. Intravascular neoplasm, particularly lymphoma, with probable concurrent thrombus formation, was prioritized. Due to the poor prognosis and subsequent development of severe anemia and melena, the patient was euthanized. Necropsy and histopathology diagnosed cervical intravascular osteosarcoma within the ventral internal vertebral venous plexus. This case represents the first description of magnetic resonance imaging features of intravascular osteosarcoma in a canine patient.

A real diagnostic challenge is posed by transfusion-dependent anemia in young patients with obscure gastrointestinal (GI) bleeding. Such a presentation can have many etiologies. Although rare, small intestinal hemangiomas are benign vascular tumors that frequently elude timely diagnosis owing to their intramural growth pattern and deep submucosal sequestration. Recent literature has increasingly shown the benefit of systemic therapies, such as sirolimus, for managing complex vascular anomalies. We report the case of a 17-year-old girl with a history of easy fatigability, melena, and exertional dyspnea, requiring regular red blood cell transfusions for the past six years. Initial laboratory investigations were suggestive of severe iron deficiency anemia, with a hemoglobin level of 6.3 g/dL and a ferritin level of 5.2 ng/mL. The stool occult blood test was positive. However, repeated upper and lower GI endoscopies and imaging were non-contributory. A repeat computed tomography angiography (CTA) of the abdomen was carried out, which showed intramural polypoidal lesions in the distal ileum and descending colon. Diagnostic laparoscopy was confirmatory of multiple small intestinal hemangiomas. In view of the multifocal nature of the lesions and the prohibitive risk of extensive bowel resection, a conservative strategy utilizing systemic mTOR (mechanistic target of rapamycin) inhibition was adopted. The patient achieved transfusion independence within two months, with a sustained normalization of hematological indices and a favorable side-effect profile. This case highlights the diagnostic complexity of small intestinal hemangiomas. It reinforces the role of imaging and laparoscopy, as well as the importance of considering rare causes, in transfusion-dependent anemia with chronic GI bleeding. In multifocal involvement of hemangiomas, sirolimus therapy may be an effective and safer alternative to surgical intervention. This case calls for more research and awareness of such rare vascular anomalies to accelerate diagnosis and management.

Familial adenomatous polyposis (FAP) is an inherited disorder characterized by the development of numerous colorectal polyps and an increased risk of extracolonic manifestations, notably desmoid tumors. Desmoid tumors are benign but locally aggressive fibrous neoplasms that do not metastasize but have a high tendency to recur. Due to their rarity, desmoid tumors often present with varied clinical features and nonspecific symptoms. We report the case of a 24-year-old man with no prior medical history who presented in March 2019 with melena, rectal bleeding, and digestive discomfort, without fever or systemic signs. Colonoscopy revealed polyposis, prompting a total colectomy with lymph node dissection in November 2019. Histopathology confirmed approximately 30 tubular adenomas with mild dysplasia; all lymph nodes were free of disease. In October 2020, the patient developed an obstructive syndrome managed by stoma creation, with successful intestinal continuity restoration in February 2021. In May 2021, abdominal swelling led to the discovery of a 17 cm ulcerated mass below the umbilicus. Imaging identified a large necrotic abdominopelvic mass and a smaller intraperitoneal mass. Histological and immunohistochemical analyses confirmed deep fibromatosis (desmoid tumor). The patient received vinblastine and methotrexate chemotherapy, resulting in significant tumor reduction. Subsequently, on September 1, 2023, he underwent extensive tumor resection with lymph node dissection. Pathology confirmed a 7 × 7 × 3.2 cm desmoid tumor with clear margins. This case highlights the critical need for vigilant monitoring in FAP patients, emphasizing early diagnosis and a multimodal treatment approach combining systemic therapy and surgery to effectively manage desmoid tumors.

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis of medium-sized arteries, and histologic confirmation is often challenging. Temporal artery biopsy (TAB) is established for suspected giant cell arteritis (GCA), but is rarely performed in PAN. We describe a 27-year-old Japanese man who presented with melena and acute visual loss in the right eye. Contrast-enhanced computed tomography revealed multiple visceral aneurysms involving the hepatic, renal, and mesenteric arteries, with active extravasation from a jejunal artery aneurysm. Ophthalmologic evaluation confirmed central retinal artery occlusion. Renal biopsy showed no evidence of vasculitis. During hospitalization, he developed a new medullary infarction, and re-examination revealed induration of the superficial temporal artery. TAB was therefore performed and demonstrated neutrophil-rich necrotizing arteritis with fibrinoid change, supporting the diagnosis of PAN. To contextualize the diagnostic role of TAB in PAN, we reviewed the literature and identified 21 TAB-confirmed cases including this patient. Most reported TAB-confirmed PAN cases underwent biopsy because GCA was initially suspected, and the histopathologic findings were heterogeneous; a neutrophil-predominant necrotizing pattern with fibrinoid change-particularly in the absence of multinucleated giant cells-may prompt reconsideration beyond GCA. The diagnostic yield of TAB in unselected PAN has not been studied, and the available evidence is limited to case reports and TAB-based cohorts. Nevertheless, TAB may be considered a pragmatic option for histologic confirmation when conventional biopsy sites are impractical or high risk, particularly in the presence of cranial ischemic manifestations or temporal-artery abnormalities.

Gastrointestinal stromal tumors (GISTs) most commonly present with gastrointestinal bleeding or as an abdominal mass, whereas spontaneous rupture with pneumoperitoneum is distinctly uncommon and portends an adverse prognosis. A 51-year-old man presented with acute hematemesis and melena of two days' duration. Contrast-enhanced computed tomography of the abdomen demonstrated a large, lobulated, heterogeneously enhancing ileal mass with central necrosis, intralesional gas, direct communication with adjacent small-bowel loops, and free intraperitoneal air consistent with tumor rupture and pneumoperitoneum. Multiple additional mesenteric and pelvic masses with smooth peritoneal thickening and mild ascites suggested peritoneal dissemination. Emergency laparotomy confirmed tumor rupture with feculent peritonitis and widespread peritoneal seeding. Histopathology established a high-grade, multifocal GIST (pT4(m)N0) with spindle-to-epithelioid morphology, increased mitotic activity, necrosis, strong CD117 and DOG1 positivity, and an elevated Ki-67 labeling index. This case highlights the characteristic radiologic features of ruptured GIST and demonstrates close radiologic-pathologic concordance in an aggressive presentation.

Duodenal neuroendocrine neoplasms (D-NENs) are uncommon tumors that account for a fraction of duodenal tumors. Although often incidentally discovered, those in the ampullary or peri-ampullary regions may present with symptoms due to biliary or gastrointestinal obstruction, including obstruction or bleeding. We describe a 65-year-old male who presented with fatigue, altered mentation, and melena. His evaluation was notable for severe anemia, metabolic derangements, and laboratory findings with concern for tumor lysis syndrome. Emergent management with hemodialysis and supportive care stabilized his condition. Esophagogastroduodenoscopy revealed a Forrest class 1B duodenal ulcer and histopathological examination of obtained biopsies confirmed a diagnosis of large-cell neuroendocrine carcinoma with a Ki-67 index of approximately 80%. Subsequent imaging demonstrated extensive hepatic involvement. Given the advanced stage of the disease and after multidisciplinary discussion, the patient elected against further oncologic intervention. This case highlights the diagnostic challenges and aggressive nature of high-grade D-NENs, emphasizing the importance of early recognition and a multidisciplinary treatment approach.

Jejunal diverticulosis (JD) is a rare condition of the small intestine characterized by acquired pseudodiverticula arising along the mesenteric border. Although most cases remain asymptomatic, complications may occur in a minority of patients and include diverticulitis, perforation, intestinal obstruction, malabsorption, and, more rarely, GI hemorrhage. Bleeding originating from jejunal diverticula is an uncommon but potentially life-threatening cause of obscure GI bleeding (OGIB). We report the case of a 59-year-old woman who presented to the ED with melena associated with symptomatic anemia. Initial gastroduodenal endoscopy failed to identify a source of bleeding. Subsequently, contrast-enhanced CT angiography of the abdomen was performed and demonstrated multiple jejunal diverticula. One diverticulum contained spontaneous hyperdense material on non-contrast images, compatible with intraluminal blood, and was associated with a dilated submucosal vascular structure, suggesting the site of recent hemorrhage. JD is a rare but important cause of OGIB. When endoscopic investigations are inconclusive, CT angiography plays a crucial role in identifying the bleeding source and guiding management. Awareness of this entity and its imaging features is essential for radiologists and clinicians involved in the evaluation of GI hemorrhage.

Hemobilia is an uncommon cause of upper gastrointestinal bleeding and represents a diagnostic challenge, particularly in patients with advanced biliopancreatobiliary disease. We report the case of a patient with pancreatic adenocarcinoma who developed massive hemobilia secondary to a gastroduodenal artery pseudoaneurysm, leading to hemodynamic instability and biliary stent dysfunction. An 82-year-old woman with a history of pancreatic adenocarcinoma under palliative management with an uncovered self-expandable metal stent presented with hematemesis, melena and presyncope. Upper GI endoscopy was performed with active bleeding through the biliary stent. Later Endoscopic retrograde cholangiopancreatography (ERCP) revealed a large intrastent clot causing obstruction. With contrast-enhanced abdominal computed tomography angiography, a pseudonaeuysm of the gastroduodenal artery. The patient subsequently underwent transcatheter arterial, achieving successful hemostasis. She was discharged seven days later with no recurrence of bleeding.

This study investigated the possible association between nicorandil and gastrointestinal adverse events using the FDA Adverse Event Reporting System (FAERS), aiming to provide more comprehensive safety guidance for clinical application and support the formulation of pharmacovigilance policies in the future. This study is a retrospective study based on FAERS. Adverse event reports in FAERS from the first quarter of 2016 to the fourth quarter of 2023 were extracted. Disproportionality analyses were employed to assess the association between nicorandil and gastrointestinal adverse events, and to conduct a further analysis of clinical characteristics. We also performed sensitivity analyses stratified by gender and age. A total of 138 reports of nicorandil-related gastrointestinal adverse events were retrieved from FAERS, with a large proportion of elderly patients (aged > 65 years, n = 98). The results of the disproportionality analysis indicated an elevated risk of gastrointestinal adverse events associated with nicorandil (reporting odds ratio:1.23, 95% CI: 1.09-1.39; information component025 = 2.43). Clinical prioritization analysis identified melaena, colonic polyp, and upper gastrointestinal bleeding as events of moderate clinical priority. Most gastrointestinal adverse events tend to occur within 1 week after the initiation of dosing. Sensitivity analyses revealed that nicorandil was significantly associated with gastrointestinal adverse events regardless of gender and age. The use of nicorandil was significantly associated with gastrointestinal adverse events. This study assists healthcare professionals in providing appropriate guidance and advice to patients prior to drug administration.