Posted 2/14/2015 5:59 AM (GMT 0)
If I remember correctly, calprotectin is a molecule that contains (binds) calcium, and it is released by white blood cells in certain inflammatory conditions. So if calprotectin is found in elevated levels in the stool, it indirectly indicates the presence and activity of increased numbers of white blood cells in the lower GI tract (mainly the colon).
So really it's a marker for measuring inflammation in the lower GI tract. It tends to increase as inflammation increases. But it's not perfect, and it's most useful for inflammation in the colon. It can be normal and sometimes miss inflammation higher upstream (small bowel).