3- IBD clinical Flashcards
what is IBD?
inflammatory bowel disease includes multiple diseases, main ones being crohn’s & ulcerative colitis →patients might not neatly fit into either of these, patients noted might have IBD/U = IBD unclassified
are symptoms good for diagnosis of IBD?
no, you usually need more than symptoms
what is problem with how immune system works in IBD?
Instead of properly distinguishing between harmful pathogens and harmless substances, the immune system in IBD reacts excessively or inappropriately to components of the gut lining, leading to chronic inflammation and tissue damage
what is immune tolerance?
the ability of the immune system to detect between gut commensals and gut pathogens
what is difference in diarrhoea for crohn’s and ulcerative colitis?
ulcerative colitis more diarrhoea with blood and crohn’s more watery diarrhoea
what is best established risk factor for IBD?
positive family history - a number of different genes have been highlighted to show linkage to IBD but unlike cystic fibrosis not one specific gene to scan for to see if have yet
what is an example of a gene related to IBD?
in chromosome 16 - mutated form of NOD2 is found in 1-20% caucasian patients with crohn’s →NOD2 encodes a protein involved in bacterial regulation
what is different with bacterial flora in colon with ulcerative colitis?
altered bacterial flora
what are 4 different thoughts of what causes IBD?
- pathogenic bacteria
- abnormal microbial composition
- if patients have defective post containment (NOD2 alteration etc) can impact how immune system deals with natural commensals
- post immune system doesn’t maintain it’s homeostasis
what areas if GI tract has lots of gut commensals?
stomach is acid = not as many commensal bacteria as other areas
bile is alkaline = more hospitable environment for commensal bacteria
moving jejunum→ileum, pH becomes less acidic and allows numbers increase and become more diverse and then in colon have much more population diversity
what happens to bacteria in crohn’s and ulcerative colitis?
in crohn’s disease →lose ability to control bacteria
ulcerative colitis →overcontrol bacteria, (maybe kill commensals)
what environmental factors can trigger flare ups?
- smoking →aggravates crohn’s but protects against ulcerative colitis
- NSAIDs →can cause inflammation within lining of gut and if used without gastric protection can cause ulcers
what is process in crohn’s from trigger to uncontrolled immune response?
people with genetic predisposition + environmental factors + secondary insult (medication, infection) →lose integrity to bowel wall →lose tolerance to own microbiome →dysbiosis (this is when thought to get problem) →increase in amount of inflammation (innate & acquired) →uncontrolled immune response (this is when patients get diagnosis as more symptoms and things can be seen)
what are different types of ulcerative colitis?
- proctitis = rectum
- left sided colitis = from rectum up to splenic flexure
- pancolitis = from rectum all the way round colon
what are symptoms of ulcerative colitis?
- diarrhoea & bleeding with diarrhoea
- increased bowel frequency (how often? - at night?)
- increased urgency
- incontinence if severe flare
- tenesmus = urge to go to toilet but no stool (sometimes can be mucous or blood)
- lower abdominal pain (lower iliac fossA)
- proctitis can cause constipation as stuff gets backed up due to inflamed
what are some important things to ask about in history?
- recent travel - could be infection
- antibiotics - could be C.diff
- NSAIDs
- family history
- smoking
- skin, eyes, joints