Inflammatory Bowel Disease Flashcards
describe the external longitudinal muscle of the large intestine
incomplete
- three distinct bands: teniae coli
- haustra are sacculations caused by contraction of teniae coli
what is IBD
group of conditions characterised by idiopathic inflammation of the GI tract, affecting the function of the gut
what are the 2 most common types of IBD
crohn’s disease
ulcerative colitis (young adults)
give an overview of ulcerative colitis
- Begins in rectum, can extend to involve entire colon
- Continuous pattern
- Mucosal inflammation (not transmural)
what are the extra-articular manifestations of IBD
- extra-intestinal: MSK pain (up to 50%), arthritis
- skin (up to 30%): erythema nodosum, pyoderma gangrenosum, psoriasis
- liver/biliary tree: primary sclerosing cholangitis
- eye: uveitis
what are causes of IBD
Genetic:
-1st degree relative increased risk
-Identical twins concordance 70%
Gut organisms
Immune response –>triggers –> antibiotics, infections, smoking, diet
how might a Crohn’s patient present
- Loose stool - non bloody
- Weight loss due to decreased nutrient absorption
- RLQ pain (position of ileum)
- Smoker
what are the examination findings of Crohn’s
- Tender mass (RLQ)
- Mild perianal inflammation/ulceration
- Low grade fever
- Mildly anaemic (blood loss due to perforation of ulcers)
what are the gross pathological features of Crohn’s
- Cobblestone appearence (on colonoscopy)
- Skip lesions
- Hyperaemia (red)
- Mucosal oedema
- Discrete superficial ulcers
- Deeper ulcers
- Transmural inflammation which leads to thickening of bowel wall and narrowing of lumen
- Can lead to formation of fistulae between bowel and bladder/vagina/skin
- Fat wrapping: mesentery thickens and wraps around small bowel
what are the microscopic features of crohn’s
granuloma formation (pathognomonic): organised collection of epithelioid macrophages
how is Crohn’s investigated
- Bloods - anaemia, FBC, ESR/CRP, C.diff to rule out other causes of diarrhoea, calprotectin always +ve in IBD
-
CT/MRI scans:
-bowel wall thickening
-obstruction
-extramural problems - Barium enema - locates strictures and fistulae
- Gross pathological changes visible during endoscopy
- skip lesions
- cobblestone
- fistulae
- strictures
what are the different types of UC
how might a patient with UC present
Passing MANY loose stools - bloody
-mucus in stools
Weight loss
Mild lower abdominal pain
Painful red eye
what might be found on examination of suspected UC patient
Mildly tender abdomen
No perianal disease - UC is only a superficial process
Normal temp
what gross pathological changes are seen in UC (2)
Pseudopolyps can develop after repeated episodes:
-Inflammation then healing
-Non neoplastic
-More common in UC (vs Crohn’s)
Loss of haustra - haustra are suculations formed by contraction of outer longitudinal muscle (teniae coli)
what microscopic pathological changes can be seen in UC
- Chronic inflammatory infiltrate of lamina propria
- Crypt abscesses (neutrophilic exudate in crypts)
Crypt distortion:
- Irregular shaped glands with dysplasia
- Darker crowded nuclei
- Reduced numbers of goblet cells
how is UC investigated
- Bloods: Anaemia and Serum markers
- Stool cultures
-
Colonoscopy:
look for continuous pattern of inflammation - Plain abdominal radiographs
- Barium enema (mild cases only)
-
CT/MRI:
Less useful in diagnosing uncomplicated UC since only superficial
compare distinguishing characteristics of crohn’s and ulcerative colitis
compare the pathological features of UC and crohn’s disease
compare endoscopic changes seen in UC and crohn’s disease
what feature of crohn’s can be seen in barium follow through
long strictures known as string sign of kantour
give 5 defining features of crohn’s
what features of UC can be seen in a double contract enema
- featureless descending and sigmoid colon: lacking haustral markings and lead pipe colon
- continous lesions without skipping
- whole colon
- mucosal inflammation: causes granular appearance
what are the medical treatments available for UC (5)
- aminosalicylates e.g. sulfasalazine for flares and remission/ 1st line for mild-moderate UC
- corticosteroids e.g. predinosolone for flares only not long term
- immunomodulators e.g. azathioprine for fistulas/maintenance of remission
- biologics e.g. anti TNF agents, anti integrins
- JAK inhibitors e.g. Tofacinitib primarily for UC
describe surgical treatment for crohn’s
- not curative
- strictures (stricturoplasty)/fistulas or abscesses by drainage
- as little bowel removed as possible
what surgical treatment is available for UC
- curable via colectomy (pan-proctocolectomy) + ileostomy
- inflammation not settling potential complications of pouchitis
- precancerous changes
- toxic megacolon: swelling and inflammation spread into the deeper layers of your colon so colon stops working and widens; can rupture in severe cases
what is looked for in stool cultures in suspected UC patients (2)
C.difficile - could be causing symptoms
Faecal calprotectin - raised when there is bowel inflammation
give an overview of Crohn’s disease
- Affects anywhere in the GI tract
- Terminal ileum involved in most cases
- Transmural (affects whole thickness of GI wall)
- Skip lesions (parts of inflammation separated by normal tissue)
what are the long term complications of IBD
- toxic megacolon
- increasing risk of colorectal cancer with increased disease duration
what are the long term complications of crohns
- strictures leading to obstruction
- fistulas (enterocutaneous, enteroenteric)
- malabsorption of nutrients e.g. Fe, B12
- small bowel cancer (screen for bowel cancer by colonoscopy, MRI small bowel)
- abscesses
why might patients with Crohns be more susceptible to gallstones
decreased absorption of bile in the terminal ileum
what are the management goals of IBD
- induce and maintain remission
- prevent complications
- improve QoL
What are the indications for surgery in UC
- fulminant disease
- chronic complications
- bleeding
- steroid dependent
what is involved in monitoring and surveillance of IBD (4)
- routine endoscopy
- disease active monitoring: CRP, FCP
- vaccines due to immunosuppressive
- lifestyle mods: low residue diet, smoking cessations in Crohns, stress management
