Feline Gastroinstestinal Eosinophilic Sclerosing Fibroplasia (FGESF) is considered to be a type of uncontrolled inflammation that affects the gastrointestinal (GI) tract. This disease was discovered and classified fairly recently (first mentions appear to be in 2007). Because this is such a young disease there is still relatively little known about it, and there is a strong possibility that cats exhibiting GI symptoms are misdiagnosed with other conditions when they really have FGESF.
Disease Information Sites
There’s not a dedicated site to FGESF, but there is a good section covering it at the IBD Kitties site.
There is a Facebook group that is currently active and is dedicated to FGESF.