The classic symptoms of coeliac disease (celiac disease) are chronic diarrhoea, partly with heavy and also, due to the dysfunctional fat digestion, greasy-looking sticky stool (steatorrhoea), pain in the joints and muscles, loss of appetite and vomiting. Some patients experience the appearance of small itchy blisters on the skin.
Children often suffer from FTT (failure to thrive) and stunted growth.
You should absolutely NOT be observing a gluten-free diet BEFORE your visit to the medical professional! This can influence the measurement readings and makes it impossible to obtain an accurate diagnosis!
Further along the line consequences such as infertility, erectile dysfunction, depression and schizophrenic disorder appear. But there is no need to worry as these cases are rare in people who live with untreated coeliac disease. Here, too, it is essential to get a personal appointment with a medical professional!
The degree of sensitivity to gluten and the intensity of the symptoms vary individually. Some people only experience minor symptoms, such as stomach ache and constipation, even if they eat larger amounts of foods containing gluten. On the other hand there are sufferers who will react even to the smallest trace of gluten with severe symptoms.
There has been a significant change in the identification of this syndrome since the introduction of screening for antibodies in the blood specifically connected to coeliac disease. An exact diagnosis can, however, only be determined through a small intestine biopsy (also known as small bowel biopsy).
Sources:
1) Keller, R.: Klinische Symptomatik: Zöliakie, ein Eisberg. In: Monatsschrift Kinderheilkunde 2003; 151:706-714
2) Österreichische Arbeitsgemeinschaft Zöliakie
3) Vogelsang,H.; Edlinger, E.; Terler, E.; "Zöliakie - Erkrankung des Dünndarms mit hoher Dunkelziffer", in Arzt+Patient, Oktober 2009