Secretory IgA (feces)

Secretory IgA (feces) too high

A raised value may fit active defenses in the gut, for example during or after a gut infection or with irritation of the lining. There is no condition for which this measurement in stool is used to make a diagnosis. A raised value does not need treatment on its own.

Secretory IgA (feces) too low

A low value is sometimes explained as weakened gut defenses, but this is not supported by evidence. A very low or undetectable value may fit an inborn IgA shortage (IgA deficiency), which occurs in about 1 in 700 people and often causes no symptoms. This is diagnosed with total IgA in the blood, not with stool.

Useful for

In people without symptoms, an abnormal result says little, because the meaning has not been established and a passing infection or a painkiller can raise the value. With long-lasting diarrhea or abdominal symptoms, the GP uses calprotectin in the stool to rule out a chronic inflammation of the bowel, and a blood test if celiac disease is suspected. With blood in the stool, unintended weight loss, diarrhea at night or new bowel symptoms after age 50, this test is no substitute for a visit to the GP.

How common is it?

Bowel symptoms are common: according to the guideline, irritable bowel syndrome affects about 4 in 100 adults in the Netherlands. Chronic inflammatory bowel diseases such as Crohn's disease and ulcerative colitis are much rarer; the guideline gives no Dutch figure for them. How often an abnormal result for these markers occurs in people without symptoms is not known.

Dutch medical specialists' guideline (FMS) on irritable bowel syndrome (NHG and NVMDL)