Sullied undergarments and Celiac disease

Hello,

Is it common for people with Celiac to soil themselves? There is a kid in my family with it (about 10 years old) who has accidents all the time. His mother swears it is because he has Celiac disease, and embarassed friends with the disease have come forward and said it is a common issue. He says that he cannot "tell when it is happening".

What is the verdict - are the accidents caused by Celiac, or maybe just compounded by it?

Thanks.