From the Guidelines
Gastrointestinal (GI) bleeding is primarily caused by diverticulosis, inflammatory bowel disease, neoplasms, stress ulcers, surgical anastomoses, vascular lesions such as angiodysplasia, and diverticulosis.
Causes of GI Bleeding
- Diverticulosis: accounting for 30% of cases, with approximately 75% of episodes stopping spontaneously, especially in patients requiring transfusions of <4 units of blood over a 24-hour period 1
- Inflammatory bowel disease (IBD): including ulcerative colitis (UC) and Crohn's disease (CD), where bleeding is caused by inflammation/ulceration of the bowel, and usually resolves with medical treatment 1
- Neoplasms: including cancer and polyps, which can cause bleeding due to tumor erosion into blood vessels
- Stress ulcers: which can cause bleeding due to mucosal erosion and ulceration
- Surgical anastomoses: which can cause bleeding due to anastomotic leakage or ulceration
- Vascular lesions: such as angiodysplasia, which can cause bleeding due to abnormal blood vessel formation
- Other causes: including anorectal varices, ectopic varices, and portal hypertension 1
Clinical Presentation
- Hematochezia: bright red blood per rectum, which can be caused by lower GI bleeding
- Melena: darkened, digested blood per rectum, which suggests an upper GI source of bleeding
- Hemodynamic instability: which can occur due to severe blood loss, and requires immediate medical attention 1
Diagnosis and Management
- Endoscopy: including colonoscopy and sigmoidoscopy, which can help diagnose and treat the cause of bleeding 1
- Imaging techniques: including CT and catheter angiography, which can help localize the source of bleeding 1
- Medical treatment: including intravenous fluid and blood product resuscitation, and medical therapy to control bleeding 1
- Surgical intervention: which may be required in cases of severe bleeding or hemodynamic instability 1
From the Research
Causes of Gastrointestinal (GI) Bleeding
The causes of GI bleeding are diverse and can occur from virtually anywhere in the gastrointestinal tract 2. The most common causes of upper GI bleeding include:
- Gastric ulcer (32%)
- Duodenal ulcer (28%)
- Esophageal varices (9%)
- Mallory-Weiss tear (6%) 3 The most common causes of lower GI bleeding include:
- Colonic diverticulosis (56%)
- Colonic ulcers (10%)
- Carcinoma (7%)
- Vascular ectasias (5%) 3
Risk Factors for GI Bleeding
Risk factors for upper GI bleeding include:
- Prior upper GI bleeding
- Anticoagulant use
- High-dose nonsteroidal anti-inflammatory drug use
- Older age 4 Other factors that increase morbidity and mortality include advanced age, serious comorbid conditions, hemodynamic instability, esophageal varices, significant hematemesis or melena, and marked anemia 5
Diagnostic Factors
Diagnostic tools for GI bleeding include:
- Clinical assessment
- Upper endoscopy
- Colonoscopy
- Scintigraphy
- Conventional arteriography
- Computed tomography angiography
- Magnetic resonance angiography 6