Ulcerative colitis & Crohn disease


Inflammatory bowel disease


Chronic condition

Inappropriate mucosal immune activation

Two disorders

– crohn disease

– ulcerative colitis

Ulcerative colitis & Crohn disease severe ulcerating inflammatory disease that is limited to the colon and rectum and extends only into the mucosa and submucosa

regional enteritis (because of frequent ileal involvement) may involve any area of the GI tract and is typically transmural


Teens and early 20s

Most common in north america, northern europe, and australia

IBD incidence worldwide is on the rise

Becoming more common in regions such as africa, south america, and

• asia, where the prevalence was historically low

* Hygiene hypothesis


idiopathic disorder combination of defects in host interactions with intestinal microbiota intestinal epithelial dysfunction

aberrant mucosal immune responses.

Genetics increased when there is an affected family member

> in crohn

NOD2 (nucleotide oligomerization binding domain 2) as a susceptibility gene in Crohn disease two Crohn disease –related genes ATG16L1 (autophagy-related 16-like)

& IRGM (immunity-related GTPase M

None associated with UC

• activated mucosal immunity and suppression of immunoregulation contribute to the development of ulcerative colitis and Crohn disease.

associated with

Mucosal immune responses defects in intestinal epithelial tight junction barrier function ( Crohn)

NOD2 polymorphisms

• defective transepithelial transport polymorphisms in ECM1 (extracellular matrix protein 1) (UC) defective epithelial anti-microbial function (paneth cell granule dysfunction)

Microbiota intestinal microbiota contribute to IBD pathogenesis antibodies against the bacterial protein flagellin are associated with

NOD2 polymorphisms (Crohn disease, but uncommon in ulcerative colitis ) probiotics, or beneficial bacteria may combat disease

Any area of GI

Crohn disease (granulomatous colitis) terminal ileum, ileocecal valve, and cecum

MC: limited to the small intestine alone in about 40% of cases multiple, separate, sharply delineated areas of disease (segmental distribution of the lesions skip lesions ) is characteristic aphthous ulcer cobblestone appearance


Gross (Crohn) stricture formation creeping fat

Microscopic features

Patchy distribution distortion of mucosal architecture (crypt branching and budding)

Fissures, noncaseating sarcoid-like granulomas (present in 40 –60% of cases), and transmural involvement….the typical triad crypt abscesses ulcers (fissures) are linear, serpiginous (bear-claw or rose-thorn)

Clinical features. intermittent attacks of relatively mild diarrhea, fever, and abdominal pain bloody diarrhea

Relapsing and remitting disease cigarette smoking

Iron-deficiency anemia generalized nutrient malabsorption

Extra-intestinal manifestations of Crohn disease

Uveitis migratory polyarthritis


ankylosing spondylitis

erythema nodosum clubbing of the fingertips

Pericholangitis and primary sclerosing cholangitis occur in Crohn disease but are more common in ulcerative colitis


Fibrosing strictures

Perforations peritoneal abscesses risk of colonic adenocarcinoma is increased in patients with long-standing colonic disease intestinal disease is limited to the colon and rectum usually begins in the rectosigmoid area

In some cases, it remains localized to the rectum (

MC spreads proximally, sometimes to involve the entire colon

( pancolitis ) .

Ulcerative colitis ulcerative proctitis )

Gross broad-based ulcers (unlike serpiginous of CD) pseudopolyps wet and glaring from blood and mucus mural thickening is not present, the serosal surface is normal, and strictures do not occur

Normal mucosa


Histologic features

Architectural crypt distortion

The inflammatory process is diffuse, generally limited to the mucosa and superficial

Basal plasmacytosis

Mucosal and submocosa, the muscularis propria is rarely involved

Mucin depletion

Granulomas are not present in ulcerative colitis

Relapsing disorder

Attacks of bloody diarrhea with stringy, mucoid material

Lower abdominal pain

Clinical features.

Cramps that are temporarily relieved by defecation

Extraintestinal manifestations present





Toxic megacolon

Venous thrombosis (most often in the iliac vein)


Colitis-associated neoplasia

• Risk increases sharply 8 to 10 years after disease initiation

Patients with pancolitis are at greater risk than those with only left-sided disease

Greater frequency and severity of active inflammation (characterized by the presence of neutrophils) may increase risk.


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