IBD

Question 1

List commonalities between CD and UC

Answer 1

1. Bowel inflammation
2. No proven etiologic agent
3. Patterns of familial occurrence
4. Systemic manifestations

Question 2

Contrast UC and CD

Answer 2

CD

• entire GI tract
• skip lesions
• strictures common
• transmural inflammation
• perianal disease
• fat/ vitamin malabsorption

UC

• colon only
• rectum always involved
• continuous inflammation
• strictures are rare and assumed to be cancer
• mucosal and submucosal inflammation only
• no perianal disease
• no fat or vitamin malabsorption

Question 3

Describe epidemiology of IBD

Answer 3

Caucasians>African Americans>Hispanics and Asians

Geography: norther latitudes

male predominance in UC, female predominance in CD especially during adolescence

Question 4

List three components of the pathology of IBD

Answer 4

Genetic susceptibility
Immune dysregulation
Environmental triggers

Question 5

What is believed to be the mechanism of immune dysregulation in IBD?

Answer 5

Loss of immune tolerance to normal bowel flora leading to over responsiveness of mucosal T cells

Traditionally thought that this was largely a problem of acquired immune system but no there is evidence for involvement of innate immune system

Question 6

Differentiate the immunologic phenotypes of CD vs UC

Answer 6

CD is often described as a Th1 disease because the primary mediators of inflammation are Th1 cytokines (IL-12, IFN-γ, TNF-α).

UC is often described as a Th2 disease because of studies showing increased mucosal expression of IL-5, a Th2 cytokine.

Question 7

List some candidate genes associated with IBD

Answer 7

NOD2 aka CARD15
IL-23 receptor
ATG16L1 and IRGM

Question 8

List environmental factors associated with IBD

Answer 8

• Smoking: appears to be protective for UC but a risk for CD
• appendectomy
• NSAIDs
• OCPs
• breastfeeding is protective
• diet (no specific links found)
• infectious agents (no definitive links)
• hygiene hypothesis
• stress

Question 9

Skip lesions can be seen in _______

Answer 9

Crohn’s disease

Question 10

Inflammation in Crohn’s disease is _____

Answer 10

transmural, full thickness

Question 11

List complications of Crohn’s disease

Answer 11

• stricture formation
• fistula formation
• perforation
• perianal Crohn’s: abscess
• gallstones
• adenocarcinoma of colon, risk of colon cancer if more than 1/3 of colon is involved

Question 12

How is Crohn’s disease diagnosed?

Answer 12

history and physical

Colonoscopy with terminal ileoscopy including biopsies

Question 13

Colonoscopy in a person with Crohn’s disease may show _____ ulcers

Answer 13

aphthous

small ulcers limited to the mucosa

Question 14

What will be seen on tissue biopsy that suggests a diagnosis of Crohn’s disease?

Answer 14

evidence of chronic inflammation.
Discrete, non-caseating granulomas
Longitudinal or stellate ulceration and mucosal cobblestoning

Question 15

What laboratory markers can aid in making a diagnosis of Crohn’s disease?

Answer 15

elevated CRP and ESR

possible anemia

Question 16

What imaging studies are used to make a diagnosis of Crohn’s disease?

Answer 16

CT, MRI, ultrasound, and fluoroscopic imaging (e.g., small bowel follow through or small bowel enteroclysis).

Question 17

______ is the hallmark symptom of ulcerative colitis

Answer 17

Hematochezia- bloody diarrhea

others: abdominal apin, anemia, incontinence

Question 18

In ulcerative colitis, inflammation is limited to the

Answer 18

mucosa and submucosa

Question 19

How is ulcerative colitis diagnosed?

Answer 19

colonoscopy and biopsy- erythematous and friable mucosa with superficial ulceration, rectum is always involved
pseudopolyps
tissue biopsies show characteristic crypt abscess

Question 20

The hallmark lesion of UC on biopsy is:

Answer 20

crypt abscess, collections of PMNs at base of crypts

Question 21

What lab studies aid in the diagnosis of ulcerative colitis?

Answer 21

CBC, CRP, ESR, iron studies, and liver tests

Question 22

List complications of ulcerative colitis

Answer 22

toxic megacolon
PSC
colon cancer- need routine screening
NOT fistulae, because not a full thickness disease

Question 23

Describe extra-intestinal manifestations of IBD that are related to disease severity

Answer 23

L arge joint peripheral arthritis
Erythema nodosum
Episcleritis
Aphthous ulcers of mouth (CD)

Question 24

Describe extra-intestinal manifestations of IBD that are usually related to disease severity

Answer 24

Pyoderma gangrenosum (deep skin ulcers)
Anterior uveitis

Question 25

Describe extra-intestinal manifestations of IBD that are not related to disease activity

Answer 25

Sacroiliitis
Small joint symmetric arthritis
Ankylosing spondylitis
PSC, cholangiocarcinoma (UC)

Others, rare: pericarditis, amyloidosis, autoimmune hepatitis

Question 26

What is microscopic colitis?

Answer 26

lymphocytic colitis and collagenous
colitis.
characterized by chronic watery diarrhea and normal findings on colonoscopy and radiology, but microscopic inflammation on colon biopsies.

Question 27

What is treatment for microscopic colitis?

Answer 27

discontinue NSAIDs, caffeine, and dairy

antidiarrheals

Question 28

What are the clinical features of microscopic colitis?

Answer 28

chronic or intermittent watery diarrhea which can be severe
commonly occurs with other autoimmune conditions
link to celiac disease