Hello.
It is not possible to have both crohns disease and ulcerative colitis. You can only have one or the other.
Colitis is a general term for inflammation in the colon and therefore it can be used to describe the inflammation of the colon in someone with crohns. This is what often causes confusion.
The term crohns colitis simply means that a person has crohns disease which is located in their colon.
Ulcerative colitis is a different condition entirely. It is not possible to have both as crohns affects the entire digestive system and can affect every layer of the intestines. Ulcerative colitis is restricted to the colon and only affects the surface layers of the intestine.