13-1: 1/30 - Non-Neoplastic Disease Of The Small And Large Intestine

Front 1

Examples of idiopathic inflammatory bowel disease. Describe each.

Back 1

Crohn's: granulomatous inflammn that may affect ANY portion of GI tract.

Ulcerative colitis: nongranulomatous inflammation limited to colon and rectum; extens ONLY into mucosa and submucosa; typically transmural

Front 2

What is the basic cause of inflammatory bowel disease?

Back 2

Unregulated and exaggerated local immune response to gut flora in genetically susceptible individuals.

Front 3

NOD2 Gene:
Function
Role in Disease
Associated Disease

Back 3

NOD2 Gene = intracell receptor for microorganisms expressed by epithelial cells and leukocytes

When bind microorganisms, stimulates NF-kappa B pathway leading to cytokine production.

Mutation in NOD2-->reduces activity of protein-->presistence of microbes intracellularly (leads to overcompensated immune response)

Assocd with CROHN'S DZ

Front 4

Crohn's Disease:
Presentation
Body parts affected

Back 4

Presentation: abdominal cramp, diarrhea, melena

40% small intestine
30% small intestine AND colon
30% colon
70-90% TERMINAL ILEUM

Front 5

Crohn's Disease:
Gross morphology
Histologic features

Back 5

Gross:
Skip lesions
Linear ulcers, fissures, fistulas
Wall thickening (not a superficial dz)
Creeping fat

Histo:
Mucosal, submucosal, and transmural inflammn
Non-caseating granulomatous inflammn

Front 6

Ulcerative Colitis:
Age groups affected
Presentation
Body parts affected

Back 6

Ulcerative colitis:
Affects any age group, but peak in early 20s

Features: bloody diarrhea, abdominal cramping, anemia, weight loss

Start in rectum and extends proximally (in a retrograde fashion) NO ILEAL INVOLVEMENT

Front 7

What are the long-term complications of inflammatory bowel disease?

Back 7

Dysplasia; may arise in multiple sites.

Risk highest in PANCOLITIS; also correlates w/duration of disease.

Front 8

Microscopic Colitis:
Subtypes
Pathophysiology
Presentation

Back 8

Microscopic colitis (can't be seen on endoscopy, need path)

Subtypes:
Lymphocytic and collagenous colitis

Etiology unk but assocd w/autoimmune disorders

Presentation: watery diarrhea

Front 9

Pseudomembranous colitis:
Pathophysiology
Presentation

Back 9

Due to exotoxins A and B of C. difficile after broad-spectrum Abx

Abd pain, profuse diarrhea, low grade fever

Front 10

Celiac Sprue:
Pathophys

Back 10

Sensitivity to wheat gliadin (component of gluten)

Assocd w/HLA-DQ2, DQ8, which are activated by gliadin.

CD4 recognizes these peptides and secretes IFN-gamma which directly damages gut epithelium

CD8's come and do more harm

Result is diffuse flattening of surface villi and malabsorption

Front 11

Celiac Sprue:
Presentation
Age of presentation
Treatment
Complications

Back 11

Present from infancy to adulthood

Syx: diarrhea, malabsorption, anemia

Tx: removal of gliadin from diet

LT complications:
Lymphoma (T-cell)

Front 12

Celiac Sprue:
Gross pathology

Back 12

Flattening of villi and atrophy (most severe proximally)

Front 13

Meckel's Diverticulum:
Body part affected

Back 13

within 30 cm of ileocecal valve

mostly asyx

Front 14

Intestinal atresia:
Most common form
Presentation

Back 14

Duodenal atresia most common (stenosis less common)

leads to neonatal intestinal obstruciton

Front 15

Imperforate anus:
Pathophys
Presentation

Back 15

Failure of cloacal diaphragm to rupture-->neonatal intestinal obstruction

Front 16

This disorder involves loss or dysfunction of ganglion cells.

Back 16

Hirschprung's Dz

Front 17

Ischemic bowel disease:
Arterial vs venous causes
Transmural vs Mural/Mucosal (General)
Chronic effects

Back 17

Arterial: atherosclerosis, emboli, vasculitis, aneurysm

Venous: hypercoag states, POST-OP, peritonitis

Can be transmural (infarction of all wall layers, due to sudden occlusion)
Can be mural/mucosal (necrosis of only mucosa and submucosa or mucosa only; due to hypoperfusion)

Chronic IBD-->inflammn, ulceration, mucosal atrophy, fibrosis-->strictures in some cases

Front 18

Ischemic Bowel Disease:
Transmural vs Mucosal/Mural Syx

Back 18

Transmural: older invididuals, bloody diarrhea, may perforate (sepsis!), 75% mortality

Mucosal/mural: nonspec abdominal complaints; intermittent bloody diarrhea, may do OK if vasc compromise corrected

Front 19

Diverticulosis:
Pathophys

Back 19

Low fiber diet-->low stool bulk-->increase peristaltic contractions-->inc intraluminal pressure-->formation of diverticula (outpouching of bowel wall)

Clinical: lower abdominal cramping, constipation

May lead to diverticulitis