Large Intestine and IBD Flashcards
What lines the LI?
Columnar ep
What are the functions of the LI?
Removes water from all indigestible gut contents
Prod certain vits
Temporary storage
Describe the muscle of the LI
External longitudinal muscle is incomplete
3 distinct bands (teniae coli)
What are haustra?
Sacculations in the LI caused by contraction of teniae coli
Outline water absorption in the colon
Facilitated by ENaC
Induced by aldosterone
What is IBD?
Inflammatory bowel disease
Group of conditions characterised by idiopathic inflam of the GI
2 types = crohns, UC
Affect function of the gut
Describe crohns
I FACTS
I - Ileum involved in most cases
F - Fistulae A - Affects anywhere in GI tract C - Cobblestone T - Transmural S - Skip lesions
Describe UC
BE CALM
B - Begins in rectum
E - Extends to entire colon
C - Continuous pattern
A - Abscesses
L - Lead pipe (loss of haustra)
M - Mucosal inflam
What systemic problems are seen in IBD?
MSK = pain 50%, arthritis
Skin = 30%, erythema nodosum, pyoderma gangrenosum, pseoriasis
Liver/biliary tree = primary sclerosing cholangitis (PSC)
Eye = 5%
What are the causes of IBD?
Genetic
Gut organisms
Immune response triggered by = Abx, infect, smoking, diet
Outline the presentation of crohns
Tender mass (RLQ)
Mild perianal inflam/ulceration
Low grade fever
Mildly anaemia
Describe the macroscopic appearance of crohns
Hyperaemia
Mucosal odema
Discrete superfical ulcers
Deeper ulcers
Transmural inflam = thickening of bowel wall, narrowing of lumen
Cobblestone appearance
Fistulae = bowel – bowel/bladder/vagina/skin
What is seen in the microscopic appearance of crohns?
Granuloma formation
How is crohns investigated?
Bloods = anaemia
CT/MRI = bowel wall thickening, obstruction, extramural problems
Barium enema = stricture, fistulae
Colonoscopy
Outline the presentation of UC
Mildly tender abdo
No perianal disease
Normal temp
