What is IBD?
A spectrum of disease characterised by chronic relapsing inflammatory conditions of the bowel.
Made up of crohn’s and ulcerative colitis
What criteria do we use to classify IBD?
THe montreal classification uses:
- Extent of disease
- Disease behaviour (strictures, penetration etc)
What is the source of IBD?
Its thought to be some sort of environmental trigger in the genetically susceptible.
Define Ulcerative Colitis?
Continuous colonic inflammation of variable distribution & severity.
How/when does UC present
Presentation peaks at 20-40yrs
= Bloody Diarrhoea
= Abdominal pain
= Weight Loss
Also causes pseudopolyps & Ulcers
Define a pseudopolyp
A “polyp” caused by destruction of the surrounding mucosa & submucosa rather than a proper polyp growing out from the gut wall
What genes are associated with IBD?
UC - HLA gene
Crohn’s - NOD2 gene
What do we call inflammation of the rectum?
How does UC affect the risk of CRC?
Long term UC (i.e. Over 10 yrs) can lead to CRC
What are the markers of a severe UC flare up?
A severe attack is defined by 6 or more bloody stools a day + 1 of the following:
- Raised ESR or CRP
- Low Albumin
- Leucocytosis or thrombocytosis
Define leuco- & thrombocytosis
Leucocytosis - Increase WCC
Thrombocytosis - Increase platelets
How/when does crohn’s disease present?
has two peaks:
- Age 20-40s
- Women >60
- Abdominal Pain
- Weight loss & anorexia
- Malaise/lethargy/low fever
- Nausea & Vomiting
- Malabsorption leading to anaemia & vitamin deficiencies
Think logically. inflammation in the gut will make you absorp poorly so weight loos, anaemia, deficiencies.
Its an immune response so it will triger pain & general unwellness.
It will mess with passage of food causing nausea/vomiting and diarrhoea
What does crohn’s disease look like in the gut?
Histologically you can see non-caseating granulomas.
It turns the serosa a granular dark grey.
Also causes the mesentery to be thick, oedematous and fibrotic with fat wrapping it and the gut.
The wall of the gut becomes thickened and narrows hte lumen.
Its also distinctive because it affects multiple areas with healthy tissue gaps in between, this is called skip lesions
How can crohn’s be complicated?
With strictures, fistulas, abscesses and perforation.
It also incrases risk of cancer by 5x
How do we test for IBD?
With blood and stool tests:
Stool = Calprotectin level, its a biomarker of intestinal inflammation and so indicates IBD over IBS and can be used to monitor the degree of IBD and its healing.
High - ESR/CRP/platelet/WCC
Low - Albumin/Hb
Colonoscopy or Capsule Enterography
CT/MRI & Barium swallow can also be sued
What is pANCA and how useful is it?
Perinuclear antineutrophilic cystoplasmic antibody test.
Its +ve in 75% of UC cases but only 25% of Crohn’s so its useful but not definitive for diagnosing IBD and UC spefically
What features distingiush crohn’s from UC?
- Skip lesions
- Peri-anal manifestations
- non-caseating granulomas
- Goblet cell depletion
- More crypt abscesses
How does IBD present extra-intestinally?
It can cause inflammation in many other places such as the eyes, joints, liver and biliary tree and skin.
Some of the more obvious are erythema nodosum, gallstones, fatty change in the liver and in CD renal calculi (kidney stones)
Sclerosing cholangitis is a liver disease often associated with IBD, what is it?
A progressive disease of the bile ducts where inflamation causes scarring & multiple strictures, eventually leading to cirrhosis.
How do we screen for Colonic cancer in people suffering from IBD?
If they have extensive chronic colitis we will do surveillance colonoscopies.
Can either do them every 1,2 or 3 years depending on how long the colitis has been present.
Each time we will take a number of biopsies to check for dysplasia
In short how is IBD treated?
In progression from:
- 5ASAs (Aminosalicylates)
- Biologic Agents
With nutrional support when necessary
How does our care of an IBD patient change when an acute flare up causes admission?
Short term steroids
Can also use Immunosuppresant cyclosporin as a rescue therapy, surgery and biologic agents where necessary.
How are steroids used for IBD?
Most common is prednisalone.
What immunosuppresants are used for IBD?
Azathioprine spares steroid use but has a number of side effects including long term raised lymphoma risk.
Methotrexate is also used, particularly in crohn’s.
What are biologic agents?
Newish drugs such as anti-TNFAlpha antibodies (monoclonal antibodies) aka infliximab
They are given by IV or SC injection.
When would antibiotics be used for IBD?
If there is perianal crohn’s or a small bowel bacterial overgrowth you might use metronidazole
When would we regard medical therapy to have failed and surgery be necessary?
- IF the patient needs recurrent courses of steroids or has unacceptable steroid complications such as diabetes, osteoporosis or psychosis
- If you cant control the symptoms
- If they relapse before or soon after you stop treatment
How do we surgically treat IBD?
Proctocolectomy with ileostomy
Or Colectomy with an ileoanal pouch
This can be an elective procedure after meds fail to work or an emergency during a severe flare up
Its possible to remove the ileostomy from a total colectomy so the patient doesnt require a stoma bag, how is this done? What are the cons of this?
With pouch surgery.
A loop of small bowel is opened and attached to the rectum.
The patient needs to go to the toiler about as often as they empty their stoma bag (6-8 times a day) so ~60% choose to stick with the bag.
What other indications are there for surgery, particularly in crohn’s? (i.e. other than the failure of meds)
- To relieve obstruction of the small bowel
- To manage fistulae
- To manage intra-abdominal abscesses
- To manage anal fissures, abscesses, fistulas and skin tags.