As the symptoms of celiac disease are often non-specific and highly variable among individuals, diagnosis of the disorder can be difficult. Complications often arise when diagnosis of celiac disease is delayed, gluten is still consumed and the disease is left untreated. Some of the complications of celiac disease include malnutrition, osteoporosis, cancer, small bowel ulcers and collagenous celiac disease. Malnutrition Damage to the villi in the lining of the small intestine affects the absorption of nutrients, leading to malnutrition. It can result in weight loss and low red blood cell count (anemia). Malnutrition in children can also cause delayed growth and development. Osteoporosis Malabsorption of nutrients and minerals, such as calcium and vitamin D, can lead to loss of calcium and bone density (osteoporosis) in adults. Cancer People with celiac disease have an increased risk of developing certain forms of cancer such as small intestinal lymphomas (cancer of lymph glands of the small intestine), small intestinal and esophageal carcinomas (cancers of the inner lining of the small intestine and esophagus). Other common cancers that are also likely to arise in people with celiac disease are cancers of the oral cavity, liver and large intestine. Small bowel ulcers Small bowel ulcers are repeated occurrences of small intestinal ulcerations and narrowing of the lumen of the small intestines. Small bowel ulcer, also referred as ulcerative jejunoileitis, is a risk factor in developing intestinal lymphomas. It can result in bleeding, weight loss, abdominal pain and obstruction of the intestines. Collagenous celiac disease Collagenous celiac disease results when the symptoms of celiac disease fail to improve, even in those following a strict gluten-free diet. As a result of the continued symptoms, scar tissue (collagen) forms just underneath the intestinal lining. References: Love K (Jan 2015). 10 Symptoms of Celiac Disease. Health Information, Rubio-Tapia A, Murray JA (2007). The liver in celiac disease. Hepatology 56(5): 1650-1658.