The small bowel, also known as small intestine is an important organ which is necessary for the absorption of nutrients. This organ is known to be the largest portion of the gastrointestinal (GI) tract. The reason why is called “small” is that it is thin or narrow when compared to the large bowel. However, the small intestine is much longer than the large intestine.
Bleeding from the small bowel occurs when there is an abnormality in the inner lining of the intestine. This bleeding can be slow which may result in anemia or it can be rapid resulting in hemorrhage. Nearly 5% of GI bleeding occurs from the small intestine.
What are the causes of small bowel bleeding?
The causes of bleeding from the small intestine are different from those that bleed from the large intestine or the stomach.
About 30% to 40% of small bowel bleeding is from abnormal blood vessels that are found within the wall of the small bowel. These abnormal blood vessels are given the term, arteriovenous malformations (AVMs) or angioectasias. The incidence of AVM’s increase as the people grow older and is associated with other medical problems such as chronic kidney disease (CKD) and valvular heart disease. In people above the age of 50 years, the most common cause of small bowel bleeding is arteriovenous malformations (AVM’s).
The other causes of small bowel bleeding include:
- Benign and malignant tumours
- Crohn’s disease