It appears usually between 6 and 24 months or so of age. While the condition is clearly genetically determined, other environmental factors must play a role in the development of the disease. The disease itself is characterized by withering of the microscopic finger-like villi that comprise the lining of the small intestine. These projections dramatically increase the surface area of the small intestine, and make absorption of nutrients as efficient as possible. Hence food is not absorbed properly, which in turn causes malnutrition, diarrhea, and all the other manifestations.
Chronic diarrhea is the most common symptom.
Symptoms also include failure to thrive, irritability, vomiting, poor appetite, foul stools, abdominal pain, excessive appetite, and rectal prolapse. Diagnosis is by a blood antibody test and small bowel mucosal biopsy. Treatment consists of a strict gluten-free diet, which must be adhered to for life. All wheat, rye, and barley products are eliminated from the diet, generally with the help of a dietician. The outlook for a child with celiac disease is good, as long as the diet is maintained.