Normally, your small intestine is lined with tiny, hair-like projections called villi. Resembling the deep pile of a plush carpet on a microscopic scale, villi work to absorb vitamins, minerals and other nutrients from the food you eat. Celiac disease results in damage to the villi. Without prominent villi, the inner surface of the small intestine becomes less like a plush carpet and more like a tile floor, and your body is unable to absorb nutrients necessary for health and growth. Instead, nutrients such as fat, protein, vitamins and minerals are eliminated with your stool.
While the exact cause of celiac disease is unknown, doctors have discovered that it often runs in families. If someone in your family has been diagnosed with celiac disease, you may have an increased risk of the disease. Researchers have discovered that some gene mutations seem to increase the risk of celiac disease, but having those gene mutations doesn't mean you're certain to have celiac disease. This means that other risk factors play a role in whether you'll develop celiac disease.
Also, celiac disease and the tendency to get celiac disease runs in families. If one member of a family has celiac disease, the odds are that about one in ten of their first-degree relatives will also have it. People may harbor this tendency for years or even decades without showing signs or getting sick. Then, some kind of severe stress, like childbirth, infection, physical injury, or surgery can "activate" celiac disease.
While the precise mechanism of this activation, and of the intestinal damage is unclear, removal of gluten from the diet usually brings about quick relief of symptoms and promotes intestinal healing in most patients.