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.
In other words, a normal d-Dimer can virtually rule out a new blood clot, but an elevated d-Dimer will not confirm that a clot is there. There are instances in which a patient may have a new clot and not have an elevated d-Dimer, but these instances are rare (less than 5% of patients). Patients with less clinically important clots (small clots and/or clots in superficial veins) are more likely to have a normal d-Dimer.