Name the layers of the GI tract
Where does UC start and stop?
Starts at rectum
Stops at Ileocaecal valve- but there may be ‘reflux ileitis’
Large intestine (rectum, colon, appendix)
Starts in rectum
Extends proximally for a varying distance (10-20% total)
Pathology of UC
(unless there is ulceration)
Diffuse active chronic inflammation
Cryptitis, crypt abscesses
Crypt architectural distortion
Reduced goblet cells
CAN CAUSE TOXIC MEGACOLON
Manifestations of UC?
Related to disease activity:
Unrelated to disease activity:
Primary Sclerosing cholangitis
Probability of cancer with UC?
20 years 2.5%
30 years 7.6%
40 years 10.8%
Factors aiding Cancer in UC?
extent of disease (little increase in proctitis)
duration of disease
association with primary sclerosing cholangitis
family history of colorectal cancer
age of onset
number and severity of relapses
inflammatory polyps or strictures
long term effective treatment & chemo-prevention
Colitis Screening protocol?
Pathology of cancer in UC?
Signs of Crohns?
Any part of GI tract
Discontinuous (Skip lesions)
Enteric / enterocolic
Focal lymphoid aggregates
Patchy, focal cryptitis, crypt abscesses
Relative preservation of crypt architecture
Toxic dilatation of colon unusual
Extraintestinal and liver manifestations as UC
Colorectal cancer risk increased when widespread colonic involvement (as UC)
Causes of Crohns?
‘Western’ disease, increasing incidence
Genetics (CARD15 - NOD2 protein)
Initiated by infection?
Infective Entero-colitis causes?
Mimicking ulcerative colitis
Mimicking Crohn’s disease
Bacterial Colitis (Dysentry) causes?
Enterotoxigenic Escherichia coli (O159)
Pseudomembranous colitis causes?
Antibiotics disrupt normal bowel flora that inhibit C. diff overgrowth
Toxin detectable in stool
Volcano lesions on biopsy
Treated by metronidazole or vancomycin
Signs of Amoeba infection?
Amoebic liver abscess
Schistosomiasis infection information?
S. mansoni, japonicum
Africa, Far East
Predisposes to colorectal cancer
Intestinal TB info?
Mycobacterium tuberculosis or M bovis
Terminal ileum & caecum
Closely mimics Crohn’s disease
Granulomas usual and caseating (unlike Crohn’s disease)
May progress to peritoneal tuberculosis
Yersinia infection information?
Yersinia pseudotuberculosis and Y enterocolitica
Meat (pork) and dairy products
Acute self limiting ileo-caecitis with necrotising granulomas
Examples of Colitis?
Deficiency of luminal (bacterial) nutrients
Causes and signs of microscopic colitis?
Chronic watery diarrhoea
General health good
Normal endoscopy and radiology
Seronegative, non-destructive arthritis
non-steroidal anti-inflammatory drugs