Inflammatory bowel disease / Irritable bowel disease Flashcards
What is the definition of Crohn’s disease?
a disease of unknown aetiology that is characterised by transmural inflammation of the GI tract and can affect any part from mouth to anus
Crohn’s disease is found as skip lesions
Which parts of the bowel are usually affected by Crohn’s disease?
- terminal ileum (close to the ileocaecal valve)
- peri-anal region
What is transmural inflammation?
inflammation that affects the whole thickness of the bowel wall
What does the inflammation associated with Crohn’s disease eventually lead to?
inflammation results in ulceration
as all layers of the GI tract are affected, the result is non-caseating granuloma formation
What are the risk factors for Crohn’s disease?
- family history
- smoking
- oral contraceptive pill
- diet high in refined sugars
- ? NSAIDs
- ? not being breast fed
it is a combination of genetic & environmental factors
What is the epidemiology of Crohn’s disease?
- seen in Ashkenazi Jews
- it has a bimodal peak seen in 15-40s and 60-80s
What is the typical presentation of Crohn’s disease?
abdominal pain:
* can be crampy or constant but is SEVERE
* affects the RLQ + peri umbilical region (terminal ileum)
diarrhoea:
* severe diarrhoea (10+ times daily) that can be nocturnal
* can contain mucus, pus or blood occasionally
peri anal lesions:
* skin tags, fistulae, abscesses
other symptoms include:
* weight loss (due to malnourishment)
* painful oral lesions
* fatigue
What are the 2 extra-intestinal skin lesions associated with Crohn’s disease?
pyoderma gangrenosum:
* small red/purple bumps or blisters that eventually erode into painful ulcers
* rapid progression
* affects the legs
erythema nodosum:
* swollen fat under the skin causes dark red patches on the shins
What are the other extra-intestinal manifestations associated with Crohn’s disease?
- arthropathy (joint pain)
- uveitis
- episcleritis
affects 20-40% patients
EI manifestations are more common when Crohn’s colitis / perianal disease are present
What is often a consequence of inflammation affecting all layers of the bowel wall down to the serosa?
patients with Crohn’s are more prone to strictures, fistulas and adhesions
What features may be seen on examination of a Crohn’s disease patient?
abdominal tenderness:
* this is usually in the right iliac region (lower right)
* there may be a mass if inflammation causes everything to “stick together”
oral examination:
* presence of painful apthous ulcers
peri-anal lesions:
* skin tags, fistulae, abscesses
Why is Crohn’s disease associated with malabsorption?
- decreased absorption of bile acids results in secretory diarrhoea
- depletion of the bile salt pool leads to malabsorption of fat, steatorrhoea + increased risk of gallstones
- malabsorption results in depletion of fat-soluble vitamins (A, D, E & K)
- severe ileal disease can result in vitamin B12 malabsorption
What blood tests are performed in a Crohn’s patient and what might they show?
- FBC / iron studies show anaemia of chronic disease
- raised inflammatory markers (CRP + ESR)
- low vitamin B12 and vitamin D
- faecal calprotectin may be raised
Inflammatory markers are NOT diagnostic but they can be used for monitoring disease progression
What might be seen on a plain AXR in Crohn’s disease?
bowel dilation
- small bowel - dilation > 3cm is abnormal
- large bowel - dilation > 6cm is abnormal
- caecum - dilation > 9cm is abnormal
this is remembered by the 3, 6, 9 rule
What might be seen on a CT scan in Crohn’s disease?
bowel wall thickening + skip lesions
What is meant by a “bowel series”?
What might this show in Crohn’s disease?
bowel series = XR + barium enema
rose thorn ulcers:
* deep ulcers seen in a stenosed ileum with a thickened wall
string sign of Kantor:
* this is indicative of fibrosis + strictures
What is the gold-standard + diagnostic test for Crohn’s disease?
colonoscopy + biopsy
colonoscopy:
* shows a “cobblestone” appearance, ulcers and skip lesions
histology:
* shows transmural involvement with non-caseating granulomas
histology is confirmative of the diagnosis
What is the first line drug to induce remission in Crohn’s disease?
steroids (glucocorticoids) IV, topical or oral
typically prednisolone is used
budenoside is an alternative in a small subgroup of patients
this is an inflammatory disease - steroids will dampen down the immune response
What other medications (other than steroids) may be used to induce remission in Crohn’s disease?
immunomodulators:
* oral or IV
* this includes azathioprine, mercaptopurine or methotrexate
* these are used as an add-on therapy / not in isolation
biological therapy:
* IV
* includes infliximab and adalimumab
* used as an add-on therapy in refractory disease / fistulating Crohn’s
What is the difference in inducing remission if a Crohn’s patient has an acute presentation?
steroids + immunomodulator are given IV opposed to oral
What are the adjuncts added on to therapy to induce remission in Crohn’s?
- smoking cessation
- perianal disease mx (usually metronidazole)
- nutritional support
If a patient has steroids + immunomodulator + biologic and still has not entered Crohn’s remission, what is done?
surgery
- this is for severe remission / presentation, refractory disease + obstruction
- usually involves colectomy or Hartmann’s procedure
if obstruction results from severe stricturing, this is a SURGICAL EMERGENCY
What is the problem with providing surgery for Crohn’s disease?
it is NOT curative, and only works for symptom managment
- can remove the severely affected part / obstruction
- the disease can re-grow at the site of anastomosis
After the symptoms have been controlled, what is the treatment for maintaining remission in Crohn’s disease?
Immunomodulators:
* this is azathioprine, mercaptopurine and methotrexate
+/- Biologics:
* this is infliximab and adalimumab
the regime depends on individualised disease + progress
systemic corticosteroids are NOT effective in retaining remission and have many side effects from long-term use
What adjuncts may be given to maintain remission in Crohn’s disease?
- anti-spasmotics for cramp relief
- anti-diarrhoeals
What is the definition of UC?
diffuse inflammation of the colonic mucosa affecting the colon + rectum only
How is the inflammation in UC different to Crohn’s?
- inflammation affects the mucosa only
- inflammation is continuous (not patchy) but only present in the colon + rectum
Where is the is the inflammation found in UC?
- the inflammation starts in the rectum
- it extends proximally
- varying lengths of the colon are affected
What causes UC?
What other condition is it associated with?
- there is no known cause but it has an environmental + genetic component
- it is associated with the HLA-B27 gene, which is also seen in ankylosing spondylitis
What are the risk factors for UC?
- family history
- HLA-B27
- not smoking (smoking is protective for UC)
What is the epidemiology for UC?
- seen in Western countries
- more common in males
- has a bimodal peak of 20-40 and around 60
What are the presenting symptoms of UC?
- BLOODY DIARRHOEA is the main symptom
- rectal bleeding + mucus
- abdominal pains + cramps
- tenesmus
- weight loss
in Crohn’s, the diarrhoea is profuse but not necessarily bloody
What are the extra-intestinal manifestations associated with UC?
- ankylosing spondylitis
- peripheral arthritis
- erythema nodosum
- pyoderma gangrenosum
- episcleritis
- uveitis
What signs might be seen on examination in UC?
- abdominal tenderness
- pallor due to anaemia
- DRE shows gross or occult blood
occult blood = not visible to the eye
What blood tests might be performed in UC?
- FBC - to look for signs of anaemia
- raised inflammatory markers (CRP / ESR)
- LFTs - UC is associated with primary sclerosing cholangitis
What other tests may be performed in UC?
- increased faecal calprotectin indicates inflammation
- pANCA is positive in 70% cases
What might be seen on a plain XR in UC?
- dilated bowel (> 6cm)
- thumbprinting (sign of bowel wall thickening due to oedema or inflammation)
What might be seen on a double contrast barium enema in UC?
lead pipe colon
- complete loss of haustral markings throughout the colon
- colon appears smooth-walled / cylindrical like a lead pipe
this sign can be seen on plain XRs and XRs using barium contrast
What is the first line and diagnostic investigation for UC?
colonoscopy:
* shows continuous erythema, bleeding + ulcers
biopsy / histology:
* shows crypt abscesses + deletion of goblet cell mucin
What is the normal diameter / features of the small and large bowel on AXR?
How can UC be categorised as mild, moderate or severe?
Mild:
* < 4 stools daily with small amount of blood
Moderate:
* 4-6 stools daily with varying amounts of blood
* no systemic changes
Severe:
* > 6 stools daily with features of systemic upset (pyrexia, tachycardia, anaemia, raised CRP/ESR)
What is the treatment to induce remission in mild-moderate UC?
Mesalazine (5-ASA):
* topical aminosalicylate is given at first
- if remission is not acheived in 4 weeks, an oral aminosalicylate is given in addition
Corticosteroids:
* if remission is not acheived within 4 weeks of oral mesalazine, oral beclamethasone is given
What is the treatment for inducing remission in severe UC?
- IV steroids are first line
- IV ciclosporin can be used if steroids are contraindicated
- if no improvement after 72 hours, add IV ciclosporin to IV corticosteroids or consider surgery
this should be treated in hospital
What is the first line treatment for maintaining remission in UC?
- topical aminosalicylate (mesalazine) +/- oral aminosalicylate
What other steps can be taken to maintain remission in UC?
following severe relapse / 2+ exacerbations/yr:
* immunosuppressives such as azathioprine / mercaptopurine are given
- biologics such as infliximab / adalimumab can be added on top
methotrexate is NOT recommended in UC
What surgery may be performed in UC?
Why is this a better alternative than in Crohn’s disease?
- total colectomy can cure the disease as it is confined to the colon / rectum
- the small bowel is joined to the rectum to create a “J-pouch”
What are the 3 major complications of UC?
- toxic megacolon
- primary sclerosing cholangitis
- colonic adenocarcinoma
also at increased risk of strictures, leading to obstruction + perforation
What is meant by coeliac disease?
a systemic autoimmune disease triggered by dietary gluten peptides called gliadin
gliadin is found in wheat, rye and barley
What are the consequences of coeliac disease on the intestine?
- villous atrophy
- hypertrophy of intestinal crypts
these features will be seen on histology and result from repeated exposure to gluten
What are the risk factors for coeliac disease?
Who tends to be affected?
- family history
- IgA deficiency
- T1 DM
- autoimmune thyroid disease
- irritable bowel syndrome
it is more common in Western countries and females
What are the genetic associations of coeliac disease?
strongly associated with HLA-DQ2 and HLA-DQ8
What is the typical presentation of coeliac disease?
it presents with vague / non-specific abdominal symptoms such as:
- diarrhoea (chronic / intermittent)
- bloating
- abdominal pain / discomfort / distention
- N & V
What are the extra-intestinal manifestations of coeliac disease?
dermatitis herpetiformis:
* this involves bilateral itchy vesicles / plaques on the elbows
others:
* prolonged fatigue
* weight loss
* symptoms of B12 / iron / folate deficiency
What are the potential complications associated with coeliac disease?
- anaemia - iron, folate + B12 deficiency
- hyposplenism
- lactose intolerance
- osteoporosis / osteomalacia
- subfertility
What is the first-line serology investigation for coeliac disease?
immunoglobulin A tissue trans-glutaminase (IgA tTG)
- this will show an elevated titre
endomyseal antibody (IgA) is sometimes used to look for selective IgA deficiency
but this gives a false negative coeliac result
What is the diagnostic investigation for coeliac disease?
endoscopy + biopsy showing villous atrophy and crypt hyperplasia
typically done in the duodenum, but can also be done in the jejunum
What is involved in the management of coeliac disease?
GLUTEN FREE DIET !!
- patients are offered the pneumococcal vaccine as they often have some degree of hyposplenism
- vitamin + mineral supplements
What is the definition of irritable bowel syndrome?
a chronic condition characterised by recurrent abdominal pain associated with bowel dysfunction
aetiology / pathology is not well understood
it is thought to involve altered gut reactivity against various stimuli (foods, bacteria, stress, toxins)
How can IBD be classifed?
What are the risk factors for IBD?
- family history
- PTSD
- history of physical / sexual abuse
- acute bacterial gastroenteritis
it is more common in females < 50
What is the typical presentation of IBS?
- abdominal cramping in the lower / mid abdomen
- alteration of stool consistency between diarrhoea / constipation
- defecation RELIEVES abdominal pain / discomfort
examination in these patients is NORMAL
When should the diagnosis of IBS be considered?
if the patient has had the following for at least 6 months:
- A - abdominal pain and/or
- B - bloating and/or
- C - change in bowel habit
What are the criteria that must be present in order to make a positive diagnosis of IBS?
abdominal pain relieved by defecation OR associated with altered stool consistency +
2 of the following:
- altered stool passage (straining, urgency, incomplete evacuation)
- abdominal bloating / hardness
- symptoms worse by eating
- passage of mucus
What is significant about the investigations for IBS?
there are NO diagnostic tests for IBS and it is a diagnosis of exclusion
What tests might be performed to exclude other conditions before a diagnosis of IBS is made?
to exclude coeliac:
* anti-tTG
to exclude IBD:
* faecal calprotectin
* CRP / ESR
* colonoscopy
to exclude CRC in high risk groups:
* FBC (anaemia)
* FOB test
What lifestyle advice is given to someone with coeliac disease?
- have regular meals / avoid missing them
- drink at least 8 cups of fluid daily
- restrict tea / coffee to < 3 cups
- reduce intake of alcohol / fizzy drinks
- increase dietary fibre intake to avoid constipation
What is involved in the medical management of IBS?
for pain:
* antispasmodic agents
for constipation:
* laxatives (avoid lactulose)
* linaclotide considered if patient does not respond to max doses of conventional laxatives + constipation for 12 months
for diarrhoea:
* first line is loperamide
