While most often constipation is caused by the lack of roughage (green vegetables etc) in your diet, it can also be caused by something called celiac disease. This means that exposure to even small amounts of gluten, like a breadcrumb, is enough to cause an autoimmune reaction, where your immune system starts attacking your own enzymes in order to keep the intestines healthy. This disease attacks the microvilli, the finger-like projections that line the small intestine, inhibiting proper absorption of nutrients. As a result, your colon, and then your small intestine, back up. This in turn inhibits gastric juices entering your stomach, resulting in reflux and heartburn and reducing nutrient absorption. Besides, keeping toxins inside the body causes additional stress on the immune system. Celiac disease is a serious condition that needs to be medically treated It is important to get the tests done, especially if you experience symptoms like constipation, bloating, abdominal pain, very dry skin, muscle soreness, weight loss, mouth sores and fatigue.