From the Guidelines
Lower gastrointestinal (GI) bleeding is commonly caused by diverticulosis, accounting for approximately 30% of cases 1, as well as other factors such as inflammatory bowel disease, neoplasms, stress ulcers, surgical anastomoses, vascular lesions, and diverticulosis.
Causes of Lower GI Bleeding
- Diverticulosis: accounting for approximately 30% of cases 1
- Inflammatory bowel disease: such as ulcerative colitis and Crohn's disease, which can be exacerbated by non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen 1
- Neoplasms: such as colorectal cancer
- Vascular lesions: such as angiodysplasia, which is often associated with the use of anticoagulant medications such as warfarin and aspirin 1
- Stress ulcers: and surgical anastomoses
- Hemorrhoids: and ischemic colitis, which are also significant contributors to lower GI bleeding 1 The risk of lower GI bleeding increases in patients taking antiplatelet agents like clopidogrel for extended durations 1.
Risk Factors
- Age: the incidence of lower GI bleeding increases with age, with a significant rise in incidence after the age of 65 1
- Anticoagulant use: the use of anticoagulant medications such as warfarin and aspirin increases the risk of lower GI bleeding 1
- NSAID use: the use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen increases the risk of lower GI bleeding 1
From the Research
Causes of Lower Gastrointestinal (GI) Bleeding
The causes of lower GI bleeding can be attributed to various factors, including:
- Diverticulosis, which is the most common cause of lower GI bleeding 2, 3, 4, 5
- Vascular malformations, such as angiodysplasia 3, 4, 5
- Cancer, including colonic neoplasia 3, 4, 5
- Inflammatory bowel disease, including ischemic and infectious colitis 5
- Anorectal diseases, such as benign anorectal disease 4, 5
- Arteriovenous malformations 5
- Use of nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin, and anticoagulants, which can increase the risk of lower GI bleeding 2, 6
Risk Factors
Certain medications can increase the risk of lower GI bleeding, including:
- NSAIDs, which can increase the risk of lower GI bleeding by 1.4 times 6
- Low-dose aspirin, which can increase the risk of lower GI bleeding by 2.1 times 6
- Anticoagulants, which can increase the risk of lower GI bleeding by 4.2 times 6
- Other non-aspirin antiplatelet agents, which can increase the risk of lower GI bleeding by 2.0 times 6
Diagnostic Considerations
The diagnosis of lower GI bleeding often involves colonoscopy, which can successfully identify the origin of bleeding in 74-82% of cases 5. Other diagnostic tools, such as nuclear scintigraphy, computed tomography, angiography, and capsule endoscopy, may also be used to evaluate lower GI bleeding 4.