In the small bowel, 30 to 40% of bleeding is caused by abnormal blood vessels in the wall of the small bowel. These abnormal blood vessels have many names, including angioectasias, angiodysplasias, or arteriovenous malformations (AVMs).he small bowel (or small intestine) is the longest portion of the gastrointestinal (GI) tract. It is called small because it is thin or narrow compared with the large bowel (also known as the colon), but it is much longer than the large bowel (14 feet on average).
Don't forget the multiple causes of an elevated d-dimer: 1  PE/DVT. 2  Sepsis/infection. 3  Malignancy. 4  Renal disease. 5  Pregnancy. 6  MI. 7  Stroke.
Elevated D-dimer, although not specific for AAD is a highly sensitive marker of the condition. D-dimer has high negative predictive value and likely rules out AAD. High index of suspicion should be maintained for the patients with chest pain in ED and D-dimer should be used as screening test to rule out AAD.