What is Crohn’s?
Chronic progressive patchy inflammation of the gut wall
- Causes transmural patchy inflammation anywhere in the GIT (from mouth to rectum)
Consists of flares and remissions
Fistulae and strictures can occur
Hyperplasia and luminal invasion
RLQ masses occur
What causes Crohn’s?
Poor tolerance to bacteria in the gut
Autoimmune response
Genetic predisposition
Often multifactorial and idiopathic
Generally more debilitating than UC due to multiple surgeries being required
What is dysbiosis?
Imbalance between the good and the bad bacteria
What genetic factors are thought to be involved in Crohn’s?
Variation in
- CARD15 gene on chromosome 16
- Increased risk in caucasians
What causes the immune response in IBD?
Inappropriate and ongoing activation of the mucosal immune system due to:
- Defective mucosal barrier and microbial clearance
What is ulcerative colitis?
Chronic progressive generalised epithelial ulceration
- Inflammation limited to the colon in the GIT
- widespread mucosal inflammation (superficial)
- not commonly associated with fistulae and strictures
Acute condition can occur rapidly and become life threatening
What are crohn’s and ulcerative colitis classified as?
Inflammatory bowel disease (IBD)
What age group has the peak onset?
20 - 40 years old
but can occur in elderly/children
What genetic factors are thought to be involved in UC?
Variations in:
- IL-10 gene (chromosome 1)
- ARP2C region (chromosome 2)
- Increased risk in south asians
What environmental factors affect risk of Crohn’s?
Refrigerators Western food preparation (not exposed to bacteria, thus when exposed triggers immune response) Smoking MAP Contraceptive pill NSAIDs Stress
What is MAP?
Mycobacterium avium subspecies paratuberculosis
- Last resort treatment is intensive anti-MAP therapy (antibiotics)
- More evidence needed, but bacteria found in cows/sheep which survives pasteurisation in dairy products
What environmental factors affect risk of UC?
Smoking cessation Western food prep NSAIDs Stress Pollution
What are RLQ masses and what are they associated with?
Right lower quadrant abdominal masses
- Crohn’s disease
Endoscopy image of Crohn’s
Mucosal inflammation
- Redness
- Oedema
- Friability, granular appearance
- Cobblestone-like (indicating deep inflammation)
Endoscopy image of UC
Redness
Granular appearance
Friability (looks weak and easily bleeds)
What are the primary complications of Crohn’s disease?
Strictures
Fissures
(others include malabsorption- anaemia; small bowel obstruction; abscess; bowel cancer; osteoporosis; lactose intolerance)
What are strictures and how are they managed?
Narrowing of the bowel lumen causing obstruction and sudden pain
- can lead to haemorrhages and perforations
- identified through CT scans
TREATMENT
- Endoscopic balloon dilatation (remove)
- Strictureplasty (cut through and reshape)
What are fistulae?
Abnormal passageway forming between one organ to another, or to the external environment
e.g. Enterocutaneous (bowel to skin); enteroenteric (bowel to bowel)
What are the complications of UC?
- Electrolyte imbalance
- Toxic megacolon (acute swelling- can lead to fever/pain/sepsis)
- Severe bleeding (anaemia)
- Risk factor for colorectal cancer
What extra intestinal diseases can result from IBD?
Uveitis
Osteoporosis
Ankylosing Spondylitis
Differences between the clinical features of Crohn’s and uC?
Crohn’s
- Acute or gradual onset
- Weight loss, fever, malaise
- Anorexia
- Malabsorption and hypovitaminosis
- Frequent perianal disease (fistulae and abscess)
- Sometimes diarrhoea
- Abdominal pain and palpable tender masses (lumps in lower abdomen)
UC
- Abrupt onset
- Intense diarrhoea (with blood/mucus)
- Left sided pain (colon)
- Weightloss and anaemia
- Nausea and vomiting
- Dehydration
- Lower abdominal cramps and pain on defecation
- Fever
Disease activity score used for Crohn’s?
Harvey Bradshaw Index
- Active disease when score is not stable and changes
- 24h recording factors such as abdominal pain, abdominal mass, wellbeing, number liquid stools
Disease activity score used for UC?
Simple Clinical Colitis Activity Index (SCCAI)
- 24h recording urgency, blood/mucus in stools, general wellbeing, extracolonic frequency etc.
What is used to determine activity and severity of CD/UC?
Disease activity scores
Endoscopies
History
