What are the symptoms?

Celiac disease affects people differently. Some people develop symptoms as children, others as adults. One factor thought to play a role in when and how celiac appears is whether and how long a person was breastfed--the longer one was breastfed, the later symptoms of celiac disease appear and the more atypical the symptoms. Other factors include the age at which one began eating foods containing gluten and how much gluten is eaten.

Villi on the lining of the small intestine help absorb nutrients.

Symptoms may or may not occur in the digestive system. For example, one person might have diarrhea and abdominal pain, while another person has irritability or depression. In fact, irritability is one of the most common symptoms in children.

Symptoms of celiac disease may include one or more of the following:

recurring abdominal bloating and pain chronic diarrhea weight loss pale, foul-smelling stool unexplained anemia (low count of red blood cells) gas bone pain behavior changes muscle cramps fatigue delayed growth failure to thrive in infants pain in the joints seizures tingling numbness in the legs (from nerve damage) pale sores inside the mouth, called aphthus ulcers painful skin rash, called dermatitis herpetiformis tooth discoloration or loss of enamel missed menstrual periods (often because of excessive weight loss)

Anemia, delayed growth, and weight loss are signs of malnutrition--not getting enough nutrients. Malnutrition is a serious problem for anyone, but particularly for children because they need adequate nutrition to develop properly.

Some people with celiac disease may not have symptoms. The undamaged part of their small intestine is able to absorb enough nutrients to prevent symptoms. However, people without symptoms are still at risk for the complications of celiac disease. See Complications.

source: http://digestive.niddk.nih.gov/ddiseases/pubs/celiac/index.htm