Large bowel disease Flashcards
What are the main differences between Crohn’s and ulcerative colitis?
Crohn’s vs UC:
- Patchy and segmental vs continuous and diffuse
- Anywhere in tract vs only in colon and rectum
- Skip lesions common vs not
- Thickened bowel and stricture vs mucosal ulceration and thin wall
- Transmural inflammation vs superficial
- Granulomas vs none
- Fistulae are common vs not
- Cancer risk moderate vs very high
- Extra GI manifestations are rare vs common
What are the similarities between Crohn’s and ulcerative colitis?
both chronic, unknown aetiology, ulceration, inflammation, relapsing course, bloody diarrhoea and both increase the risk of cancer
What is Crohn’s disease?
Crohn’s disease is a chronic inflammatory disease that can occur anywhere from mouth to anus
It most commonly occurs in the terminal ileum and colon
Who does Crohn’s affect?
- Young patients so late adolescence and early adulthood
- Common in males
What is the pathology of Crohn’s disease?
- patchy and segmental disease
- chronic active colitis with granuloma formation
- increased chronic inflammatory cells will be seen in the lamina propria
- crypt branching with non-caseating granuloma
- skip lesions
- cobblestoning with thickened wall and fissures
What are the causes of Crohn’s?
- smoking
- sterile environment
- genetic defects (common gene identified is NOD2)
What is the clinical presentation of Crohn’s?
abdominal pain small bowel obstruction diarrhoea bleeding PR anaemia weight loss - symptoms depend on what part of the tract is affected
What are the test for Crohn’s?
Bloods: raised CRP, ESR, white cell and platelet
Stool tests
Imaging and colonoscopy (to determine large bowel involvement)
MRI or white cell scan to see small bowel involvement
Staging of the disease
What is the treatment for Crohn’s?
- steroids
- immunosuppressants
- anti-TNF therapy
What are the complication for Crohn’s?
- Malabsorption as iron, vitamins won’t be -Gallstones
- Fistulas between many different organs
- Anal disease
- Intractable disease
- Bowel obstruction-Perforation
- Malignancy etc
- Stricture or abscess caused by flares
What is ulcerative colitis?
- Ulcerative colitis is a chronic inflammatory disorder that is only in the colon and rectum
- It comprises of mucosal and submucosal inflammation
Who gets ulcerative colitis?
Young patients
More common in males
What is the pathology of UC?
- inflammation is confined to the mucosa and submucosa
- no granulomas in this disease
- many inflammatory cells
- irregular branching crypts
- cryptitis
- crypt abscesses
- ulceration with fibrinopurulent exudate
- always starts in rectum
What are the causes of UC?
Unknown
Possible environmental factors such as smoking, drugs, stress, hygiene and diet
What is the presentation of UC?
- diarrhoea
- mucus and blood PR
- non-GI manifestations such as uveitis, arthritis, erythema nodosum etc
- need to defecate in night and increased urgency
What are the investigations for UC?
blood tests, stool tests, imaging (extent, transition, zone, loss of vessel pattern, granular mucosa or contact bleeding), endoscopy and histology, look for polyps
What are the treatments for UC?
- 5ASA
- steroids
- immunosuppressants
- anti-TNF therapy
What are the complications of UC?
- Intractable disease
- Toxic megacolon (massively swollen colon that will rupture)
- Colorectal carcinoma
- Blood loss etc
- primary sclerosing cholangitis
What is a polyp?
a protrusion above the normal epithelial surface
What can a polyp be and what is it most likely to be?
- can be an adenoma, a serrated polyp, a polypoid carcinoma or other
- most common are neoplastic adenomas and metaplastic polyps
What are the different types of polyps classified by shape?
pedunculated, sessile or flat
What do polyps look like?
have a stalk of normal mucosa but will have an irregular surface
What are adenomas?
- benign epithelial tumour which forms from the glands
- not invasive and don’t metastasise
What are the types of adenomas?
tubular, villous or tubulovillous
What type of tissue makes up an adenomas?
dysplastic
Why are adenomas always removed?
can commonly develop into adenocarcinomas so must all be removed as they are premalignant
What are adenocarcinomas?
malignant epithelial tumours which forms from glands
What is the primary treatment for adenocarcinomas?
surgical and the colon is then sent to pathology for staging
What are the features of an adenocarcinoma?
tumour will be an ulcerating and stricturing tumour mass and can burst through the bowel wall
What are the histological features of and adenocarcinoma?
moderate differentiation and a dirty necrosis pattern
What staging is used for adenocarcinomas?
Dukes staging is used to see how far the cancer has gone and prognosis varies with this staging
- A is confined to muscularis propria
- B is through the muscularis propria
- C is metastasis to the lymph nodes
What are the possible gross appearances for adenocarcinomas?
sigmoid tumour, transverse tumour, caecal mass or nodal mets
What are the two types of inherited cancer syndromes for colorectal cancer?
hereditary non polyposis coli or familial adenomatous polyposis
What are the features of hereditary non polyposis coli?
HNPCC: late onset, autosomal dominant, right sided tumour and inflammatory response
What are the features of familial adenomatous polyposis?
FAP: early onset, autosomal dominant, defect in tumour suppressor, tumours throughout colon with no inflammatory response
What are diverticula?
pouches protruding from the intestinal wall when the mucosa and submucosa herniate through the muscle layer
Where are most diverticula found?
in the sigmoid colon and are found by accident
How is diverticular disease diagnosed?
- endoscopy
- Ba enema (white outpourings seen)
- raised inflammatory markers in diverticulitis
What are the clinical features of diverticulitis?
LIF pain or tenderness
sepsis
altered bowel habits
What are the complications of diverticulitis?
pericolic abscess perforation haemorrhage fistula stricture
How does a fistula between bladder and bowel present?
frequent UTIs
pneumaturia (air in the bladder)
How are uncomplicated diverticular disease patients treated?
oral antibiotics
no treatment
high fibre diet recommended
How is complex diverticulitis treated?
Hartmann’s procedure
primary resection or anastomosis
What is colitis?
inflammation of the colon
What are the causes of colitis?
infective
ulcerative
Crohn’s
ischaemic
How does acute colitis present?
bloody diarrhoea
abdominal cramps
dehydration
sepsis
What are some other common features of chronic colitis?
weight loss
anaemia
How is colitis diagnosed?
XR
sigmoidoscopy for biopsy
stool culture
What is the treatment for colitis?
IV fluids
IV steroids
resting of GI tract
surgery if the colitis doesn’t settle
What is ischaemic colitis?
- occurs in the elderly
- can be an acute or chronic occlusion of the IMA
What is colonic angiodysplasia?
a vascular abnormality that causes GI bleeding in the right side of the colon
How is angiodysplasia treated and diagnosed?
- difficult to diagnose
- treated with embolisation, endoscopic ablation and surgical resection