IBD Flashcards
what causes IBD?
idiopathic autoimmune disease
course of UC?
relapsing remitting
pattern of inflammation in UC?
continuous inflammation of mucosa and submucosa only
only in large bowel
rectum always affected
what is backwash ileitis ?
severe UC where entire colon is affected and inflammation continues up into ileum and small bowel
ileum is oedematous
occurs in 20% of UC patients
how does smoking affect UC?
protective
often flares when people stop smoking
who is UC most common in?
equal genders
peaks in early 20s and again in 40s/50s
what is seen on endoscopy in UC?
granular, hypervascular and mildly oedematous mucosa with loss of vascular pattern
other pathology in UC?
lack of fibrosis
neutrophilic infiltration leading to crypt abscess
pseudopolyps
loss of haustrations (lead pipe colon)
can lead to dysplastic changes and adenocarcinoma
what does Proctitis mean in terms of UC?
rectum only involved
what does proctosigmoiditis mean in terms of UC?
rectum and sigmoid involved
what does left sided colitis mean in terms of UC?
involvement up to splenic flexure
40% of UC patients
what does extensive colitis mean in terms of UC?
involvement up to hepatic flexure
20% of UC patients
what does panproctocolitis mean in terms of UC?
whole colon involved
may get backwash ileitis due to imcompetent iliocaecal valve
what are the cardinal symptoms of UC?
bloody diarrhoea = main symptom also - stool mixed with mucus - tenesmus - abdo pain - systemic upset - extra-intestinal symptoms
what might abdo distension and tenderness in context of UC indicate?
toxic megacolon
extra-intestinal symptoms in UC?
enteropathic arthritis sclerosing cholangitis cholangiocarcinoma erytheme nodosum pyoderma gangrenosum uveitis episcleritis
describe enteropathic arthritis?
large joints affected
asymmetrical oligoarthritis
usually knees, ankles, elbows, wrists and sometimes axial (spine, hips etc)
how is UC severity scored?
truelove and witt score
mild UC?
<4 stools a day
only small amount of blood
no systemic upset
mod UC?
4-6 stools per day
varying amounts of blood
no systemic upset
severe UC?
> 6 bloody stools/diarrhoea a day
features of systemic upset
what size of transverse colon indicates toxic megacolon?
> 6cm
basic investigations in UC?
FBC: raised WCC and neutrophils, anaemia
Us&Es: rules out AKI, hypokalaemia and hypobilirubinaemia
raised CRP
blood and stool culture: excludes infective colitis
imaging in UC?
AXR
thumbprinting (Mucosal thickening of haustra)
lead pipe colon: loss of normal haustra
toxic megacolon
other investigations in UC?
varium enema (lead pipe colon) CT scan (shows thickening of colon wall)
what test is diagnostic of UC?
colonoscopy + biopsy (differentiated crohns and UC)
how is medical management used to induce remission in acute presentation of UC?
proctitis: topical 5-ASA is first line
proctosigmoiditis: topical 5-ASA
extensive disease: combined topical and oral 5-ASA
(may add oral 5-ASA as well as topical or a short course of steroids in proctitis/proctosigmoiditis if topical not inducing remission in 4 weeks)
how is remission maintained with medical management in UC?
5-ASA topical, oral or both
oral azathioprine if 2 exacerbations in 12 months requiring systemic corticosteroid therapy
when is surgery indicated in UC?
acute colitis that fails to respond to medical therapy
chronic symptomatic colitis on max medical therapy or bad side effects of therapy
perforation
complications such as neoplasia
most common surgery in UC?
proctocolectomy with ilioanal pouch formation
(removes colon and rectum and ileum folded into a pouch and reattached to anus - ileal resevoir functions as sort of new anus)
when is a proctocolectomy with end ileostomy used in UC?
patient or anus not suitable for restorative procedure due to either advanced age, impaired anal sphincter etc
when is sub-total colectomy with ileostomy used? (sigmoid and rectum left in place)
safest procedure to do in an emergency when patient is very unwell
rectosigmoid stump can be brought up as a mucus fistula while everything is healing and then reversed and reattached
pattern of inflammation in crohns?
chronic inflammatory, non-caseating, granulomatous disease
full thickness inflammation (transmural)
affects any part of the GI tract so can crop up anywhere
but mostly starts in terminal ileum and caecum
how is smoking associated with crohns?
risk factor
makes it worse
who does crohns usually affect?
peak onset in teens and early 20s (younger than UC)
what is fat wrapping?
type of pathology seen in crohns
affected bowel looks blue-grey and thickened with spiral surface vessels and encroachment of the mesenteric fat around the bowel (fat from mesentery attached to the bowel creeps up and around the bowel)
what causes “cobblestoning” in crohns?
mucosal thickening and fissuring ulceration (mucosa thickens, then fissures form causing deep lines in the thick mucosa = cobblestones)
how does stenosis occur in crohns?
extensive fibrosis and smooth muscle hyperplasia
describe the transmural inflammation in crohns and what happens in the bowel wall
lymphoid aggregates form in the subserosal tissues forming “crohns rosary”
also causes mucosal crypt ulceration and fissuring ulceration
complications in crohns disease?
perforation
fistula formation
abscess formation
how does crohns affect the anus?
can cause
- superficial ulcers with undermined edges (relatively painless)
- rectovaginal fistula (communication between rectum and vagina causing leakage of gas and faeces from vagina)
- incontinence as a result of destruction of anal sphincter muscle
how can crohns affect the upper GI tract?
oral ulceration
dysphagia
oesophageal involvement or upper abdo pain
gastric outlet obstruction with gastroduodenal involvement
how does crohns present?
inflammatory features - abdo pain - altered bowel habit (not bloody) - weight loss - fever - failure to thrive in children features of a fistula stenosis symptoms perianal disease (fissures and fistulae)
features of stenosis?
colicky abdo pain
small bowel obstruction
weight loss
can have food fear as eating can worsen colicky abdo pain as bowel is trying to push food past stricture
basic investigations in crohns?
FBC: raised WCC and neutrophils, anaemia
Us&Es: hypokalaemia, hypoalbuminaemia, rule out AKI
CRP: raised
blood and stool culture: excludes infective colitis
imaging in crohns?
AXR not really needed as dilation not really a feature in crohns but often done anyway
usually go straight to CT which shows inflammatory mass, abscess, perforation etc
OGD or colonoscopy used depending on site affected
barium enema: can show narrowing or irregularity in small bowel
MRI: used in anal disease
diagnostic test in crohns?
colonoscopy + biopsy
how is remission induced in crohns?
mono-therapy with systemic IV glucocorticoid (prednisolone, hydrocortisone)
consider enteral nutrition in kids where concerned about growth retardation
may add azathioprine to glucocorticoid to induce remission
infliximab used in severe, non-responsive cases
how is remission maintained in crohns?
oral azathioprine mono-therapy
methotrexate if azathioprine allergic due to TPMT enzyme deficiency
principles of surgery in crohns?
remove as little bowel as possible
surgery done to deal with complications, not cure
indications for surgery in crohns?
perforation, haemorrhage, severe colitis, obstruction
abscess or fistula
steroid dependency, dysplasia/cancer
failure of medical treatment
what surgeries are used in crohns?
segmental resection (just single bit of disease taken out and ends reattached)
colectomy with iliorectal anastomosis
subtotal colectomy with iliostomy
ileocaecal resection
how can IBD and IBS be differentiated?
IBS is relieved by passing stool
IBD causes tenesmus - doesnt feel like youve emptied bowels, always feel a need to pass more so not relieved by passing stool
