The purpose of this research study is to collect different types of samples (such as stool, swabs, urine) to form a biorepository. This repository will provide valuable samples from people with and without IBD so that investigators can learn more about the cause of IBD, and different therapies that could be used to treat it. These samples will be used for future gastrointestinal research. Because technology and scientific understanding may advance quickly, it is not yet known what specific studies the samples may be used for.

The purpose of this study is to characterize the microbiome in children with Crohns disease who have perianal fistula and to compare it to other children with Crohns disease who do not have perianal disease. Studying the role of the microbiome in perianal fistula may help us to develop new therapies.