Inflammatory Bowel Disease (IBD) & Large Bowel Flashcards
What is a polyp?
Protrusion above an epithelial surface
A tumour (swelling)
Pedunculated - has a stalk
Commonest polyp?
Adenoma
What must happen to all adenomas?
They must be removed.
Potentially pre-malignant
Different types of polyps
- Adenoma
- Serrated polyp
- Polypoid carcinoma
- Ohter
What is a serrated polyp?
Sessile (flat) polyp lesion of the colon
What kind of necrosis is seen in large bowel cancers?
Dirty necrosis (looks like it has been flecked with dirt)
Dukes Staging
A: Confined by muscularis propria
B: Through muscularis propria
C: Metastatic to lymph nodes
Colorectal carcinoma - right and left sided presenting complaint
75% Left sided (rectum, signed, descending)
- blood PR, altered bowel habit
- obstruction
25% Right sided
- anaemia, weight loss
- do not normally obstruct (except at ileocoecal valve)
Common metastatic sites in colorectal carcinoma
Local - mesorectum, peritoneum
Lymphatic spread - mesenteric nodes
Liver
Inherited Cancer Syndromes
HNPCC
FAP
how many polyps in each
HNPCC//
Hereditary Non Polyposis Coli
<100 polyps
- late onset
- autosomal dominant
- inherited mutation
- right sided tumours
- Crohn’s-like inflammatory response
FAP//
Familial adenomatous Polyposis
> 100 polyps to 1000s
throughout the colon
adenocarcinomas
EARLY onset
autosomal dominant
defect in tumour suppression
Diverticular Disease
what is it
complications
True/false diverticula
Out-pouchings of the large intestine
Complications//
inflammation (diverticulitis) rupture abscess fistula massive bleeding
Ischaemic colitis
histopathologically
complications
common in
“withering of crypts”
pink smudgy lamina propria
fewer chronic inflammatory ells
Common in: elderly
Complications: massive bleeding, rupture, stricture
Antibiotic Induced PSEUDOMEMBRANOUS colitis
Common in?
Bacteria responsible?
Patchy yellow membranous exudate on mucosal surface (looks like a scabby steak)
Explosive lesions on mucosa
Patients on broad spectrum antibiotics
Clostridium difficile - toxin A and B attack lining
Bloody diarrhoea
Antibiotic induced pseudomembranous colitis - treat with?
Vancomycin
or colectomy
Collagenous Colitis
Increase in thickness of sub epithelial collagen
Patchy disease
Watery diarrhoea, normal endoscopy
Lymphocytic colitis
Normal mucosa
Watery diarrhoea
MASSIVE increase in intraepithelial lymphocytes
possible coeliac disease
RADIATION COLITIS
Small ulces
Areas of mucosal haemorrhage
ecstatic mucosa
HISTORY of cervical carcinoma
Telangectasia - spider veins
due to chemo/radiotherapy
Acute infective colitis
Infection
Cryptitis
Neutrophils
May be onset of IBD
IBD - the 2 (main) types
Ulcerative colitis
— diarrhoea and bleeding
Crohn’s disease
— abdominal pain and peri-anal disease
Smoking and IBD
Aggravates Crohn’s
Protects against UC
Ulcerative Colitis - clinical features
Inflammation of colon
Affects rectum, extending proximally
affects mucosal layer only
What is inflammation of the rectum called?
Proctitis
Pancolitis
UC that affects the whole large intestine
Backwash ileitis
Ileocoecal valve is swollen and there is some patchy inflamed tissue in the distal ileum.
due to pancolitis
UC - symptoms
Diarrhoea + BLEEDING
Mucous and blood PR
Increased bowel frequency
Urgency
Tenesmus - feeling of unfinishedness
Incontinence
Night rising
Lower abdo pain - LIF
Proctitis - constipation
Who is UC most common in/peak incidence?
20s and 30s
Severe UC
How many stools/day
Other symptoms
> 6 bloody stools
+ one of
> Fever
Tachycardia
Anaemia
Elevated ESR
Mucosal oedema in UC is known as? 👍
Thumb printing
What is TOXIC MEGACOLON
Dilatation of colon
Transverse >5.5cm
Caecum >9cm
UC - Ix
Bloods
AXR
Endoscopy
Biopsy
UC - endoscopy
Endoscopy
- define extent of disease
- loss of vessel pattern
- granular mucosa
- contact bleeding
- pseudopolyps (surviving mucosa)
- Loss of haustra
- Crypt distortion
UC - histology
- Absence of goblet cells
- Crypt distortion
- Abscess
- Affects mucosal layer only
UC - complications
Extra-intestinal manifestations
↑ Risk of colorectal cancer
determined by - severity of inflammation, duration and disease extent.
Toxic megacolon - acute or acute on chronic fulminant colitis, colon swells up to massive size
will RUPTURE unless removed
–> emergency colectomy
Colorectal carcinoma - chronic inflammation leads to epithelial dysplasia and then carcinoma
Blood loss
Electrolyte disturbance
Anal fissures
Intractable disease - continuous diarrhoea, total colectomy, flare ups
Extra-intestinal//
deranged LFTs
Oxalate renal stones
PSC - stricture within bile duct
–>Chronic inflammatory disease of biliary tree –> cholangiocarcinoma
Uveitis Stomatitis Steatosis Erythema nodosum arthritis ankylosing spondylitis Pyoderma gangrenous, erythema nodosum
Crohn’s affects everywhere from…
Bum to gum
What kind of lesions are present in Crohn’s
Skip lesions
Discontinuous inflammation (unlike UC)
Granulomatous
Crohns has mucosal/transmural inflammation?
Transmural
Does Crohn’s have exacerbations?
Yes (as does UC)
Perianal crohn’s disease
Recurrent abscess formation
Pain
Fistulae - persistent leakage
Damaged sphincters
Crohn’s disease phenotypes
Stenosis of oleo-coecal valve
Inflammation
Fistuale within the intestine (from ileum to sigmoid)
Strictures causing distension of the proximal bowel
Crohn’s symptoms are determined by…?
The site of the disease
Crohn’s - symptoms
S.I.//
Abdo cramps (peri-umbilical)
Diarrhoea
Weight loss
Colon//
Abdo cramps (lower abdo)
Diarrhoea (sometimes w/blood)
Weight loss
Mouth//
Painful ulcers
Swollen lips
Angular cheilitis
Anus//
Peri-anal pain
abscess
fistulae
Crohn’s - on examination
Clinical
Bloods
Colonoscopy
Histology
Clinical//
Evidence of weight loss
RIF mass (inflamed bowel/abscess)
Peri-anal signs
Bloods//
CRP Albumin Platelets B12 Ferritin
Colonoscopy//
Crohn’s has “fat wrapping” and cobblestoned appearance of mucosa
“Fat creeping”
Thickened wall
Histology//
Patchy Granuloma (non caseating)
Most common site of Crohn’s?
Ileocoecal region
Small bowel assessment
Barium follow through
Small bowel MRI
Technetium-labelled white cell scan
Typical Patient
22 years old Male Abdo pain Bloody diarrhoea for 3/12 Tender abdomen
Patchy, segmental disease with “skip” areas, anywhere in GI tract
Crohn’s disease
What kind of granuloma is crohn’s associated with?
Non-caseating granuloma
Typical endoscopic signs in Crohn’s
Fissuring (ulceration destroys the mucosa)
Stricturing of terminal ileum
Thickening of bowel wall
Cobblestoning
Pseuodpolyps
TRANSMURAL inflammation
Cryptitis
Crypt abscesses
Complications of Crohn’s
Malabsorption
- – short bowel syndrome
- – Hypoproteinaemia
- – vitamin deficiency
- – anaemia
- – gallstones
Fistulae
Anal disease
- sinuses
- fissures
- skin tags
- abscesses
- skin tags
Intractable disease Bowel obstruction Perforation Malignancy Amyloidosis Toxic megacolon extra-GI conditions are rare
What can repeated resections lead to?
Short bowel syndrome
Pathogenesis of Crohn’s
Genetics
Environmental triggers/
- smoking
- infectious agents
- vasculitis
- sterile environment theory
- NSAIDs
Abberant immune response
- persistent activation of T cells and macrophages
- excess pro-inflammatory cytokines
Is Toxic megacolon more likely in Crohn’s or UC?
UC
32 yo
Female
Bloody diarrhoea and mucous
Goes to toilet 25 times a day
diffuse, continuous disease involving rectum
Ulcerative colitis
Histology - UC
Irregular-shaped branching crypts
— acute cryptitis
Crypt abscesses
Ulceration
- – fibrinopurulent exudate
- – broad base
What are aphthous ulcers most commonly associated with
Coeliac disease and Crohn’s disease
Ulcers in Crohn’s and UC
Crohn’s - fissure like ulcers
UC -horizontal, box like, undermining ulcers
Lifestyle advice for IBD
Avoid smoking
Diet (can influence symptoms)
Drug therapy for Crohn’s
Steroids
Immunosuppressants
Anti-TNF therapy
Drug therapy for UC
5ASA (mesalazine)
Steroids
Immunosuppressants
Anti-TNF therapy
5ASA mechanism & side effects
Topical effect
Anti-inflammatory
Reduces risk of colon cancer
side effects: diarrhoea, idiosyncratic nephritis
can be taken as:
Prodrug
pH dependent release
Delayed release
Suppositories
Enema
Corticosteroids in IBD
Anti-inflammatory
Prednisolone/Budenoside
Induce remission
Short course
Immunosuppression IBD
When most potent suppression of inflammation required (if steroids are not working)
Azathioprine
Methotrexate
Mercatopurine
Azathioprine
what drug should be avoided when prescribing this one?
Immunosuppressant
TPMT activity –> toxicity
Avoid ALLOPURINOL
Side effects//
pancreatitis
leukopoenia
hepatitis
lymphoma (small risk)
Anti TNF-alpha therapy
Proinflammatory cytokine
Anti TNF promotes the apoptosis of activated/effector T lymphocytes
rapid mucosal healing in responders
TNF antibodies
Infliximab
Adalimumab
Infliximab
TNF antibody
Adalimumab
TNF antibody
When to use anti TNF
Part of long term strategy - including immune suppression; surgery (Crohn’s) supportive
Refractory/fistulising disease
Exclude current infection (like TB)
What disease is 5ASA used for?
Ulcerative colitis
Surgery in IBD
Emergency//
- failure to respond to medical therapy
- small bowel obstruction
- abscess, fistula
Elective//
- failure to respond to medical therapy
- dysplasia of colonic mucosa
- best scenario
(patient prepped for outcome)
Crohn’s - surgery
Minimise amount of bowel resected
NOT curative
Repeated resection can lead to small bowel syndrome and lifelong parenteral nutrition
Surgery for UC
CURATIVE
Option of permanent ileostomy
Restorative proctocoloectomy and pouch
