inflammatory bowel disease Flashcards
what is inflammatory bowel disease?
chronic, relapsing, remitting inflammation of the GI tract
what are examples of inflammatory bowel disease?
Crohn’s disease
ulcerative colitis
what do Crohn’s disease and ulcerative colitis differ in?
location and inflammation
when does inflammatory bowel disease commonly present?
teens and twenties
mean age is 29.5 yrs
what can IBD be due to?
genome
microbiome
environment
is IBD medelian inherited?
no, but has genetic susceptibility
what kind of genetic variation makes people genetically susceptible to IBD?
SNPs (single nucleotide polymorphisms)
what percentage of someones offspring who has IBD will also develop IBD?
10%
What do genes that cause inflammatory bowel disease regulate?
- epithelial barrier
- immune response
- bacterial handling
what is the pathogenesis of IBD?
pathologic gut → altered microbiota
damaged epithelial barrier → increased bacterial adhesion and translocation
→ chronic inflammation occurs
what is the ratio of microbial cells in the gut lumen to eukaryotic cells in the human body?
10:1
how many different species of bacteria are present in the gut?
at least 500 different species
what is the metabolic activity of all gut bacteria equivalent to?
that of the liver
what part of the gut contains the most bacteria?
colon
what is different in the microbiota of people with IBD compared to those without?
in IBD there is dysbiosis in microbial communities
what kind of bacteria is massively more present in people with IBD than those who do not have it?
proteobacteria
describe ulcerative colitis
continuous inflammation in colon (begins at rectum and works proximally)
male = female
symptoms: bloody diarrhoea, abdominal pain, weight loss, fatigue
features: no goblet cells, crypt absecces, mucosal inflamamtion
describe proctitis
inflammation confined to rectum only
symptoms:
- frequency, urgency, incontinence,
- tenesmus, constipation (proximal faecal stasis), stool has small volume mucous and blood
treatment: topical therapy
what investigations are done for ulcerative colitis?
bloods: inflammatory markers
stool culture: rule out infection
faecal calprotectin: elevated (>200)
colonoscopy and colon mucosal biopsies
what are examples of markers of inflammation checked for in ulcerative colitis?
normocytic/microcytic anaemia
increased CPR/WCC/platelets
decreased albumin
what is faecal calprotectin?
protein biomarker released when there is inflammation in colon
describe acute severe colitis
presentation: patients often appear well
>6 bloody stools/day &
fever/tachycardia/anaemia
what must be done within the first 24 hours of a patient being admitted with acute severe colitis?
- blood tests
- stool chart
- stool cultures: for c. difficile
- avoid non-steroidal analgesics, opiates, anti-diarrhoels, anti-cholinergics
- IV glucocorticosteroids
- IV hydration
- LMWH
- Abdomen x-ray
describe Crohn’s disease?
inflammation in the digestive tract
presentation: diarrhoea, abdominal pain, weight loss, malaise/lethargy, anorexia, malabsorption (anaemia, vitamins)
features: skip lesions, granulomas, transmural inflammation
what are the investigations for Crohn’s disease?
bloods: inflammatory markers
stool culture: rule out infection
faecal calprotectin
colonoscopy
MRI small bowel study
capsule endoscopy
CT
what are possible complications of Crohn’s disease?
- inflammation
- stricture
- fistula
what is perianal Crohn’s disease?
inflammation at or near the anus
symptoms: perianal pain, pus secretion, unable to sit down
investigations: MRI pelvis, EUA
treatment: surgery (drain abscess and place seton stitch), antibiotics, biologics (anti-TNF)
what are differential diagnoses of IBD
- other causes of chronic diarrhoea: malabsorption, IBS
- ileocaecal TB
- infective, amoebic and ischaemic colitis
what kind of approach does management of IBD use?
step up approach
what medication is given to treat Crohn’s disease by reducing inflammation?
aminosalicylates (5-ASAs)
what are aminosalicylates?
these work by blocking prostaglandins and leukotrienes
not effective in Crohn’s disease
when are steroids used
to induce remission in both Crohn’s and UC
prednisolone
budesonide
when are immunomodulators used
for maintenance in crohn’s and UC
azathioprine
methotrexate (crohn’s only)
what biologics are used
Anti-TNFa antibodies: infliximab, adalimumab
A4b7 integrin blockers: vedolizumab
what surgery is used for acute severe colitis
subtotal colectomy
rectal preservation
ileostomy
what are extra-intestinal manifestations of IBD
- mouth ulcers
- skin rashes/lesions
- musculoskeletal
- eyes
- primary sclerosing cholangitis
describe pouch surgery
only for UC
mobilise and lengthen small bowel → construct pouch
