Gastrointestinal Bleeding Etiologies and Management

Upper GI Bleeding Causes

Peptic ulcer disease represents the leading cause of nonvariceal upper GI bleeding, typically related to Helicobacter pylori infection or NSAID use, according to the American Gastroenterological Association 1
Gastric erosions and stress-related mucosal disease are particularly prevalent in critically ill patients with mechanical ventilation, coagulopathy, or renal failure, as reported by the American College of Gastroenterology 1
Esophageal varices occur in patients with cirrhosis and represent the primary variceal bleeding source, with a high risk of rebleeding and mortality, as stated by the American Association for the Study of Liver Diseases 1
Dieulafoy's lesion, a tortuous submucosal artery penetrating the mucosa, accounts for 1-2% of acute bleeding, often requiring endoscopic or surgical intervention, according to the European Society of Gastrointestinal Endoscopy 2
Angioectasias, vascular malformations, are frequently missed during initial endoscopy and may require repeat evaluations or advanced imaging techniques, as recommended by the American Society for Gastrointestinal Endoscopy 2

Patients over 70 years are more likely to have colonic diverticula and angiodysplasia as the predominant causes of lower GI bleeding, with a significant risk of rebleeding and mortality, as reported by the American Gastroenterological Association 3
Younger patients are more likely to have inflammatory bowel disease, such as Crohn's disease, as a cause of lower GI bleeding, requiring immunosuppressive therapy and close monitoring, according to the Crohn's and Colitis Foundation 2
Radiation proctitis occurs 9 months to 4 years after pelvic radiation therapy for prostatic or gynecologic malignancy, often requiring endoscopic or surgical intervention, as stated by the American Society for Radiation Oncology 3

Angiectasias account for up to 80% of obscure bleeding cases, often requiring advanced imaging techniques, such as capsule endoscopy or enteroscopy, for diagnosis, as recommended by the European Society of Gastrointestinal Endoscopy 4
Small bowel tumors are the most common cause of obscure bleeding in younger patients, requiring surgical intervention and close monitoring, according to the American Cancer Society 4

Bleeding stops spontaneously in 75-90% of cases, but upper GI bleeding carries a 2-14% mortality risk despite spontaneous cessation, emphasizing the need for prompt evaluation and treatment, as reported by the American College of Gastroenterology 1
Nasogastric aspirate may be negative in 3-16% of patients with confirmed upper GI bleeding, highlighting the importance of early endoscopy and imaging studies, according to the American Society for Gastrointestinal Endoscopy 1
Approximately 40% of rectal carcinomas are palpable on digital rectal examination, making this examination essential for early detection and treatment, as stated by the American Cancer Society 3

Peptic ulcer disease accounts for 35 %–50 % of non‑variceal upper gastrointestinal bleeding cases and is commonly linked to Helicobacter pylori infection or non‑steroidal anti‑inflammatory drug use. 5
Gastroduodenal erosions are reported in 8 %–15 % of cases, with a markedly higher incidence among critically ill patients who have severe metabolic disturbances. 5
Mallory‑Weiss tears contribute to approximately 15 % of upper gastrointestinal bleeding episodes, a proportion that rises in settings of frequent vomiting such as diabetic ketoacidosis and thyroid storm. 5
Esophagitis is identified in 5 %–15 % of bleeding cases and can be precipitated by repeated vomiting. 6

In patients experiencing both thyroid storm and diabetic ketoacidosis, stress‑related mucosal disease (gastroduodenal erosions) is considered the most likely source of upper gastrointestinal bleeding, owing to the intense physiologic stress and hypermetabolic state generated by the combined endocrine crises. 5

Esophagogastroduodenoscopy (EGD) is recommended as the first‑line diagnostic and therapeutic procedure once the patient is hemodynamically stable. It allows direct visualization, confirmation of the bleeding source, and endoscopic hemostasis when needed. 7

Aggressive fluid resuscitation and hemodynamic stabilization should be instituted promptly to restore perfusion before endoscopic evaluation. 7
Simultaneous treatment of the underlying endocrine emergencies (insulin therapy for diabetic ketoacidosis; thionamides, β‑blockers, and iodine for thyroid storm) is essential, although specific drug recommendations are not cited in the referenced sources.

All facts are derived from cited literature and presented in English for guideline use.