IBD Flashcards
What are the contributing factors of IBD?
- environmental factors (eg. Antibiotics, intestinal inf.)
- genetic predisposition
- gut microbiota
- host immune response
Describe the presentation of infective colitis
- short history of diarrhoea +/- vomiting
- abrupt onset +/- resolution of symptoms
- systemic upset
- fever
- travel + unwell contacts
- immunocompromised
What is the investigation and management of infective colitis?
Investigation:
- stool culture (x4)
- CDT
Management:
- conservative if immunocompetent (even if bacterial gastroenteritis confirmed)
Describe the presentation of ischaemic colitis
- increased risk in elderly, CV disease, HF
- abrupt onset pain + bloody diarrhoea
- +/- systemic inflammatory response syndrome (SIRS)
Describe the investigation findings and treatment of ischaemic colitis
- CT may show segmental colitis in watershed areas (areas receiving dual supply from distal branches of their arteries)
- splenic flexure + rectosigmoid junction
- treatment is usually conservative
- IV fluids +/- antibiotics (if unstable)
When should you decide to admit a patient with suspected UC?
If they are producing >6 stools a day + signs of systemic upset
What imaging is useful in colitis?
- abdominal X-ray
- assess disease extent + severity
Define megacolon + toxic megacolon
- megacolon: transverse diameter of colon >5.5cm or caecum >9cm
- toxic megacolon: megacolon + signs of systemic toxicity (EMERGENCY - risk of perforation)
What is an X-ray sign of bowel inflammation?
Thumb-printing
What are the 4 layers of the bowel?
- mucosa
- sub-mucosa
- muscularis
- sub-serosa
Describe the pathology of CIBD
Acute changes:
- acute inflammation
- ulceration
- loss of goblet cells
- crypt abscess formation (neutrophil aggregation)
Chronic changes:
- architectural changes
- paneth cell metaplasia (increased plasma cells and lymphocytes)
- chronic inflammatory infiltrates in lamina propria
- neuronal hyperplasia
- fibrosis
Describe the prescribed treatment of UC
- mesalazine
- 4.8g (in flare ups)
- 2.4g daily maintenance (decreases metaplasia and polyp formation)
At what point would you consider a treatment escalation from mesalazine in UC?
- severe relapse/frequent relapses of disease which require 2 or more corticosteroid courses within 12 month period
- azathioprine/mercaptopurine (immunosuppressants)
- biologics (anti-IL/TNF)/surgery
When treating a patient in hospital for UC when can you decide that steroid treatment is not working efficiently?
If on day 3 of treatment:
- stool frequency >8
- or CRP >45
* colectomy needed (consider surgery or medical treatment with infliximab/cyclosporin)
List the complications of UC
Local: haemorrhage, toxic dilation of colon
Systemic: skin (erythema nodosum, pyoderma gangrenosum), liver (sclerosing cholangitis), eyes (iritis, uveitis), ankylosing spondylitis, malignancy (esp. colorectal cancer)
When is endoscopic surveillance for colorectal cancer commenced in UC patients?
After 10 years of disease (where the risk of colorectal cancer increases)
What factors in a history/investigations does a Crohn’s disease diagnosis become more likely?
- family history
- evidence of malabsorption
- weight loss
What is Crohn’s disease?
- chronic inflammatory condition affecting anywhere from mouth to anus
- 2x more common in smoking
- peak incidence 15-25y
What are the symptoms of Crohn’s disease?
- abdo pain (central)
- diarrhoea (watery)
- weight loss
- fistulae (communication between internal adjacent structures), abscesses, oropharyngeal/gastroduodenal involvement
- eye symptoms (episcleritis, uveitis)
- joints (sacroilitis, inflammatory athropathy)
- skin (erythema nodosum)
Contrast Crohn’s disease vs UC
- Crohn’s can affect the small and large bowel, UC just affects large bowel
- Crohn’s is patchy inflammation giving macroscopic ‘skip lesions’, UC is confluent and diffuse inflammation
- Crohn’s is a transmural, deeply ulcerating inflammation, UC inflammation is confined to the mucosa
- Crohn’s has granulomas presence, UC does not
What is the medical treatment of Crohn’s?
- azathioprine or 6-mercaptopurine
- methotrexate (not routinely used due to side effects + teratogenicity)
- infliximab/adalimumab (anti-TNF biologics)
- vedolizumab/ustekinumab anti-cytokine)
What are the risk factors for severity/need for surgery in Crohn’s patients?
- young onset
- smoking
- perianal disease
- stricturing small bowel disease
