0:01

Okay, another question that frequently

0:02

gets asked is, "Is the disease Crohn's or is it

0:05

UC?" And it can be difficult clinically

0:09

to decide in certain cases. Oftentimes,

0:10

it's very apparent clinically, but other times it's not known.

0:14

And so, we need to talk a little bit about

0:17

the difference between the two. So we'll go through

0:20

some of the similarities and differences on the

0:22

slide, and then we'll show some cases after that.

0:25

So first of all, Crohn's,

0:27

a feature of it is skip lesions.

0:29

So if you're seeing skip lesions, it's generally

0:32

Crohn's disease, whereas UC should be confluent,

0:36

especially if untreated, it should really

0:38

start at the anus and go up through the cecum.

0:42

Now, an important caveat to that is if someone

0:44

is taking rectal medication, they can have

0:48

anal sparing and sigmoid sparing, and only

0:51

see disease in the right colon, potentially.

0:54

But that's a rarity, and generally

0:56

it should be confluent disease.

0:58

Crohn's can be anywhere from the mouth

0:59

to the anus, whereas ulcerative colitis

1:02

is isolated to the colon generally.

1:04

The one exception is the severe UC case,

1:08

where it can also get back into the ileum

1:11

because of the inflammatory changes

1:12

extending backwashing into the ileum.

1:15

Crohn's is transmural, whereas UC is not transmural.

1:19

And because of the transmural inflammation,

1:21

Crohn's can cause fistula and abscesses.

1:23

UC shouldn't cause fistula because the

1:25

outer walls of the bowel are not involved.

1:29

They both do predispose to adenocarcinoma,

1:31

and they both have extraintestinal manifestations.

1:34

So, just keep those things in mind

1:36

as complications from both diseases.

1:38

So now we'll show a few cases,

1:40

showing some UC and Crohn's and ways you need to

1:43

think about approaching the differential there.