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.

Suspected small bowel bleeding is defined as a gastrointestinal bleeding, overt or occult (iron-deficiency anemia), with unremarkable high-quality upper endoscopy and colonoscopy. The main causes are vascular lesions (angiodysplasia) and inflammatory lesions (Crohn's disease). Diagnosis is primarily based on capsule endoscopy, which has an optimal yield if performed within 48 hours on bleeding onset. Deep enteroscopy often allows targeted treatment, but its availability is limited. If the capsule endoscopy is not contributive as well, the bleeding is referred to as obscure gastrointestinal bleeding. Management is not consensual. Treatment of the anemia and surveillance may be an option. It is reasonable course of action to repeat endoscopies, optimizing them, particularly in the event of recurrence.

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.

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.

Gastric cancer usually presents late with nonspecific symptoms such as epigastric discomfort, anorexia, weight loss, nausea, anemia, or gastrointestinal bleeding. Initial presentation with osteoporosis-like manifestations and multiple bone metastases in the absence of gastrointestinal symptoms is rare.

BACKGROUND Heyde syndrome (HS) is defined by the triad of aortic stenosis (AS), gastrointestinal bleeding, and acquired von Willebrand syndrome (avWS). Diagnosis can be challenging in elderly patients with multiple comorbidities, particularly when angiodysplasia is absent on endoscopy. We present a case illustrating the diagnostic process and therapeutic outcome, emphasizing that the absence of angiodysplasia should not exclude HS. CASE REPORT A 73-year-old woman with a history of AS, coronary artery disease, hypertension, type 2 diabetes, and anemia presented with 2 weeks of melena and 1 week of fatigue. She was pale on exam with a harsh systolic murmur radiating to the carotids. Laboratory evaluation showed hemoglobin 7.7 g/dL, microcytosis, and elevated troponin consistent with type II myocardial infarction due to demand ischemia. Prior endoscopic evaluations, including esophagogastroduodenoscopy, colonoscopy, and capsule studies, revealed melena but no bleeding source. Coagulation studies assessing von Willebrand factor activity were not available from the referring facility in this case. Transthoracic echocardiogram and cardiac catheterization confirmed severe AS (aortic valve area 0.4-0.7 cm2) with concomitant coronary artery disease. The patient underwent transcatheter aortic valve replacement (TAVR). At 6-month follow-up, she was asymptomatic, with resolution of anemia (hemoglobin 14 g/dL) and negative fecal occult blood testing. CONCLUSIONS Acquired von Willebrand factor deficiency diagnostic measures were unable to be provided from the facility at which she was originally admitted. This case underscores the importance of considering HS in patients with severe AS and recurrent gastrointestinal bleeding even when angiodysplasia is not visualized. Hemodynamic shear stress in AS leads to degradation of high-molecular-weight von Willebrand factor multimers, predisposing to bleeding. The resolution of anemia and bleeding after TAVR strongly supports the diagnosis. Early recognition and valve replacement are essential for effective management.

Collagenous gastritis is a rare pediatric disease characterized by chronic gastritis with superficial, irregular mucosal involvement, focal atrophy of the gastric glands, an inflammatory infiltrate predominantly composed of lymphocytes and plasma cells, and areas of epithelial erosion. Focal collagen deposition in the subepithelial region of the lamina propria is a hallmark feature. Gastric epithelial erosions can cause hematemesis and, more generally, occult gastrointestinal bleeding, leading to chronic iron-deficiency anemia. Currently, there are no established management guidelines, and data on long-term follow-up are lacking. We report a clinical case of collagenous gastritis, emphasizing its features and therapeutic approach.

The freeze-dried rabies vaccine (Vero-cells) is generally safe. We present a rare case of a 44-year-old man who developed spontaneous intraperitoneal hemorrhage from a giant gastric gastrointestinal stromal tumor (GIST) shortly after receiving this vaccine. Emergency surgery was performed, and postoperative pathological and immunohistochemical analysis confirmed the diagnosis of a high-risk gastric GIST. The patient declined postoperative adjuvant therapy with imatinib. Follow-up evaluations at one year postoperatively indicated stable disease, and he has remained progression-free for 16 months to date, underscoring the indolent biology of gastric GISTs even in high-risk cases. This case serves as an important reminder for clinicians to consider underlying occult GISTs when evaluating acute abdominal symptoms after vaccination. Through this patient's journey, we emphasize the significance of performing comprehensive computed tomography (CT) examinations in patients with giant GISTs prior to rabies vaccination, and underscore the crucial need for heightened vigilance and close monitoring following administration of the freeze-dried rabies vaccine (Vero cells). Potential mechanisms that have been hypothesized to explain spontaneous tumor hemorrhage in this context include vaccine-induced inflammatory cytokine surges and hemodynamic changes. Although a rare case of rabies vaccine-associated thrombocytopenia has been reported, evidence for this mechanism remains limited. Further studies are warranted to clarify the relationship between vaccination and tumor rupture.