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.

Children's Hospital of Philadelphia (CHOP) is inviting healthy individuals ages 0-21 to become part of a unique opportunity to help other kids heal: the CHOP Pediatric Fecal Microbiota Transplant (FMT) Stool Bank. This unique program is the first of its kind in the United States and offers screened stool donations from healthy children that may be used to provide life-changing treatment for children suffering from serious gut infections like recurrent C. difficile - an illness that can cause significant symptoms and complications. Contributing to this program could make a direct difference in providing safe and effective treatment options for serious gut infections in children.

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.