Gastrointestinal Flashcards
(207 cards)
Define inflammatory bowel disease
Umbrella term for two main diseases causing inflammation of the GI tract:
- Ulcerative Colitis
- Crohn’s disease
They both involve inflammation of the walls of the GI tract and are associated with periods of remission and exacerbation.
Dermatological manifestation:
Erythema nodosum - related to active disease
Pyoderma gangrenosum - not related to disease acitivity
What are the features of Crohn’s disease?
NESTS
N - no blood or mucus
E - entire GI tract
S – “Skip lesions” on endoscopy.
T – Terminal ileum most affected and Transmural (all 4 layers) inflammation
S – Smoking is a risk factor (don’t set the nest on fire)
Crohn’s is also associated with weight loss, strictures and fistulas.
What is the aetiology of Crohn’s?
Still unclear, but genetic links have been found - particularly mutations in the NOD2 pathogen recognition proteins
Environmental factors possibly include smoking, oral contraceptive pill, poor diet, NSAIDs, exposure to antibiotics etc.
What is the pathophysiology of Crohn’s?
Thought to occur in genetically and immunologically susceptible individual.
- Initial inflammatory infiltrate enter into intestinal crypts
- This develops into ulceration of the superficial mucosa
- Ulceration penetrates deeper and forms non-caseating granulomas through all layers
What are the risk factors for Crohn’s disease?
- Jewish
- Affects females more than males
- Presentation mostly at 20-40 years
- Lower incidence than UC
What signs and symptoms might a patient with Crohn’s disease present with?
- Abdominal pain (right lower quadrant)
- Prolonged diarrhoea (no blood/intermittent blood and mucus)
- Weight loss
- Perianal lesions
- Fatigue
- Fever
What investigations/tests would you carry out for a patient with suspected Crohn’s disease?
- FBC - anaemia, leukocytosis
- B12 and folate deficiency
- Faecal calprotectin (released by the intestines when inflamed) - does not differentiate between CD or UC
- GOLD STANDARD:
Colonoscopy with ileoscopy and tissue biopsy is diagnostic - granulomatous transmural inflammation - C-reactive protein (CRP) indicates inflammation and active Crohn’s disease
- Stool sample - rule out C.difficile infection.
- Imaging with ultrasound, CT and MRI to detect fistulas, abscesses and strictures
What is the treatment/management for Crohn’s disease on first presentation or during a flare?
Firsr line: oral prednisolone which is a glucocorticoid steroid
If not effective, consider adding immunosuppressant meds such as Azathioprine and Mercaptopurine
What is the treatment/management for Crohn’s disease to maintain remission?
Talk to the patient, as it is reasonable not to take medication when the patient is well.
Otherwise azathioprine or mercaptopurine for maintenance treatment
When is surgery considered for a patient with Crohn’s disease?
When the disease only affects the distal ileum it is possible to resect this area and prevent further disease flares surgically.
However, Crohns typically involves the entire GI tract
Surgery can also be used to treat strictures and fistulas secondary to Crohn’s disease.
What are the possible complications of Crohn’s disease?
Fistulas, strictures (narrowing of intestine0, abscesses and small bowel obstruction
Oral prednisolone - glucocorticoid steroid
Describe:
1) Use
2) Mechanism of action
3) Main side effects
1) Crohn’s disease - first presentation or flare-up
2) Prednisolone exerts glucocorticoid effects with minimal mineralocorticoid effects
3) Increased appetite, mood swings, Cushing’s syndrome
What are the features of ulcerative colitis (UC)?
UC = CLOSEUP
C – Continuous inflammation
L – Limited to colon and rectum
O – Only superficial mucosa affected
S – Smoking is protective
E – Excrete blood and mucus
U – Use aminosalicylates (e.g. mesalazine)
P – Primary Sclerosing Cholangitis (inflammation of bile ducts)
What is the aetiology of UC?
Recognised as a multifactorial polygenic disease as exact aetiology is still unknown
Theories indicate that genetically susceptible individuals might develop UC in response to environmental triggers.
Likely an autoimmune disease initiated by an inflammatory response to colonic bacteria
What is the pathophysiology of UC?
Macroscopically:
- Limited to the colons and rectum.
- Starts at the rectum, and can progress as far as the ileocaecal valve (junction between small and large intestine)
- Continuous inflammation – no skip lesions (as in CD)
- Ulcers & pseudo-polyps in severe disease
Microscopically:
- superficial mucosa inflamed – no deeper (not transmural)
- Crypt abscesses
- Depleted goblet cells
What are the risk factors for UC?
- Jewish
- Affects males & females equally
- Presentation mostly at 20-40 years
- Higher incidence than Crohn’s
- Smoking protective against UC
What signs and symptoms might a patient with UC present with?
- Abdominal pain (lower left quadrant)
- Rectal bleeding
- Diarrhoea
- Blood in stool
- Arthritis and spondylitis
- Malnutrition
- Abdominal tenderness
What are the risk factors for UC?
- Family history of inflammatory bowel disease
- Human leukocyte antigen-B27 (suggestive of autoimmune disease)
- Non-steroidal anti-inflammatory drugs (NSAIDs)
What investigations/tests would you carry out for a patient with UC?
- GOLD STANDARD!
1) Endoscopy with biopsy and negative stool culture is diagnostic.
- Shallow ulceration
- No inflammation beyond submucosa
- Crypt abcesses and goblet cell depletion
2) Stool studies for infective pathogens - to rule out C.difficile
3) Faecal calprotectin - elevated (detects IBD but cannot differentiate between UC or CD)
4) FBC to check for anaemia, infection, thyroid, kidney and liver function
What is the treatment/management for a patient with first presentation or flare of mild to moderate UC?
To induce remission:
First line: oral or rectal aminosalicylate (e.g. sulfasalazine or mesalazine)
Second line: corticosteroids (e.g. prednisolone)
What is the treatment/management for a patient with first presentation or flare of sereve UC?
To induce remission:
Hospitalisation
First line: IV corticosteroids (e.g. hydrocortisone)
Second line: IV ciclosporin
What is the treatment/management for UC in order to maintain remission?
- Oral or rectal aminosalicylate e.g. mesalazine
- Immunosuppressants such as azathioprine or mercaptopurine
Ulcerative colitis: if conventional therapy fails, what treatment can we try?
Third-line treatment: biologics (TNF-alpha inhibitor e.g. infliximab) and Janus kinase inhibitors
Can surgery be considered for patients with UC?
Yes, as UC only affects the rectum and colon, removing them (panproctocolectomy) is curative. However, be aware of post-op complications