Inflammatory bowel disease

Question 1

What are the 2 types of IBD’s a patient could have?

Answer 1

• Crohn’s
• Ulcerative colitis

Question 2

What is Crohn’s disease?

Answer 2

Chronic granulomatous/patchy inflammatory disease that can affect any part of the gastrointestinal tract. Damage and inflammation extends beyond the submucosal layer through the entire depth of the intestinal wall (transmural).

CROHN’S ⇒ transmural, skip lesions, smoking is RF, cobblestone appearance, non-caseating granulomas, increased goblet cells, small bowel enema shows Kantor’s string sign and rose thorn ulcers.

Question 3

What causes crohn’s disease?

Answer 3

• Disorder of unknown aetiology caused by transmural granulomatous inflammation of the GI tract
• Thought to be caused by an abnormal Th1 cellular response
• As it is Th1-mediated, causes more severe inflammatory response which can penetrate all the way through the gut and affect any point of GI tract from mouth to anus.
• Most commonly/ severely affects terminal ileum (70%).

Question 4

Describe the epidemiology of crohn’s disease

Answer 4

M=F, 2 age peaks → 15-40 yrs (main peak) and 60-80 yrs
- UK annual incidence: 5-8/100,000
- UK prevalence: 50-80/100,000
- Affects any age but peaks in teens, 20s and 40s

Question 5

What are the risk factors for crohn’s disease?

Answer 5

white ethnicity, FH of CD, age peaks, smoking

Question 6

What are the presenting symptoms of crohn’s?

Answer 6

1. Crampy abdominal pain (due to inflammation, fibrosis or bowel obstruction)- RLQ Abdominal Pain → may be relieved by defecation
2. Diarrhoea (usually non-bloody)
3. Fever, malaise
4. Symptoms of complications – eye disease (uveitis), joint disease (seronegative arthritis), skin disease (erythema nodosum), anaemia
5. Lethargy
6. Transmural; malabsorbtion= weight loss and anaemia

Question 7

What signs of crohn’s can be found on physical examination?

Answer 7

1. Weight loss
2. Clubbing
3. Signs of anaemia
4. Aphthous ulcers in mouth
5. Perianal disease: skin tags, fistulae and abscesses
6. Skin Lesions → erythema nodosum (erythema on shins) and pyoderma gangrenosum (ulcers on legs)
7. Arthropathy (Joint Pain)
8. Ocular Symptoms → anterior uveitis (painful red eye with loss of vision and photophobia), episcleritis (painless red eye)

Question 8

What investigations are used to diagnose/ monitor crohn’s?

Answer 8

1. Colonoscopy + Biopsy → deep ulcers, skip lesions, cobblestone appearance
2. Histology → transmural inflammation with non-caseating granulomas
3. Barium Enema → Kantor’s string sign and ‘rose thorn’ ulcers
4. Faecal Calprotectin → raised (can help distinguish IBS and IBD)
5. FBC → anaemia due to chronic inflammation, chronic blood loss, iron malabsorption or malabsorption of B12/folate
6. Increased CRP & ESR → inflammatory markers correlate closely with activity of CD
7. Stool MC&S → exclude infections
8. Serum vitamin B12 (absorbed in terminal ileum) & Folate → reduced due to malabsorption
9. Plain AXR or CT Abdomen

Question 9

How is Crohn’s managed?

Answer 9

1. Induce Remission → Prednisolone or Budesonide (Corticosteroids)
2. Maintain Remission → 1st line- Azathioprine/Mercaptopurie or 2nd line - Methotrexate (Immunomodulators)
   - Azathioprine ⇒ may cause myelosuppression, reducing WCC.
   *Should be monitored with FBC.
   * This risk is significantly increased due to interactions with several drugs.
   * Of those listed here, allopurinol is most likely to interact with azathioprine and cause leukopenia
   - Smoking Cessation
3. Biologics → Infliximab
   (Can’t do curative surgery due to skip lesions, unlike UC which is continuous)

Question 10

What complications may arise from crohn’s?

Answer 10

small bowel obstruction (stricture and fistula formation), anaemia (terminal ileum is where B12 is absorbed) , malignancy, kidney stones, gallstones (Terminal ileitis affects the absorption of bile salts, increasing the risk of gallstone formation), perianal fistula (fistulotomy or draining seton, MRI to visualise) and abscess (incision + drainage)

Question 11

What is ulcerative colitis?

Answer 11

Chronic relapsing and remitting inflammatory disease affecting the large bowel. Form ulcers along the inner-surface/lumen of the LI. Ulcers are spots where the tissue has eroded away and left behind open sored/breaks in the membrane.  
- Starts in rectum and spreads proximally, always continuous
UC ⇒ mucosa and submucosa only, continuous, smoking is protective, crypt abscesses, decreased goblet cells, pseudo polyps, barium enema shows lead pipe appearance.

Question 12

Summarise the prognosis for patients with Crohn’s disease

Answer 12

It is a chronic relapsing condition
2/3 of patients will require surgery at some stage
2/3 of these patients require more than 1 operation

Question 13

What causes ulcerative colitis?

Answer 13

UNKNOWN
1. Possible genetic susceptibility (chr 12, 16)
2. Other factors involved: immune response to bacterial or self-antigens, environmental factors, altered neutrophil function and abnormality in epithelial cell integrity
3. Considered to be Th2 mediated – IL-13 is key
4. Positive family history - 15% of patients
5. Associations:
Elevated serum pANCA
Primary sclerosing cholangitis (70% of patients with PSC have UC)

Question 14

Summarise the epidemiology of ulcerative colitis

Answer 14

1. Higher prevalence in:
   - Ashkenazi jews
   - Caucasians
2. Uncommon before the age of 10 yrs
3. Peak onset: 20-40 yrs
4. Equal sex ratio up to the age of 40 yrs (higher in males from then on)

Question 15

what are the presenting symptoms of ulcerative colitis

Answer 15

• Bloody or mucous diarrhoea (stool frequency depends on severity of disease) → episodic or chronic
• LLQ Pain
• Tenesmus and urgency→ suggestive of proctitis
• Crampy abdominal pain before passing stool
• Weight loss
• Fever
• Extra-GI manifestations (e.g. uveitis, scleritis, erythema nodosum, pyoderma gangrenosum)

Question 16

What signs of ulcerative colitis can be found on physical examination

Answer 16

• Signs of iron deficiency anaemia (e.g. conjunctival pallor)
• Dehydration
• Clubbing
• Abdominal tenderness
• Tachycardia
• Blood, mucus and tenderness on PR examination
• Extra-GI manifestations:
  1. Joints → peripheral arthritis and ankylosing spondylitis
  2. Skin → erythema nodosum and pyoderma gangrenosum
  3. Ocular → episcleritis > uveitis

Question 17

What investigations are used to diagnose/ monitor ulcerative colitis?

Answer 17

1. Colonoscopy + Biopsy → continuous distal disease, absence of granulomas, crypt abscesses, depletion of goblet cells
   - If severe colitis, flexible sigmoidoscopy may be done instead, due to risk of perforation with colonoscopy.
2. Faecal Calprotectin → normal: simple, non-invasive test for GI inflammation (distinguish between IBS and IBD)
3. Stool MC&S → rule out infectious causes
4. LFTs → primary sclerosing cholangitis
5. Bloods → increased ESR & CRP, anaemia, leukocytosis
6. AXR → thumbprinting, loss of haustra, toxic megacolon (large bowel >6cm), pseudo polyps
   - Transverse Colon >6cm
   - Tx = NBM, IV Fluids, NGT. (Avoid Colonoscopy due to perforation risk).
7. Barium Enema → lead pipe appearance 

Question 18

What criteria is used to stratify severity of ulcerative colitis.

Answer 18

Truelove & Witt’s criteria:
mild: < 4 stools/day, only a small amount of blood
moderate: 4-6 stools/day, varying amounts of blood, no systemic upset
severe: >6 bloody stools per day + features of systemic upset (pyrexia, tachycardia, anaemia, raised inflammatory markers)

Question 19

How is ulcerative colitis managed?

Answer 19

TO INDUCE REMISSION:
Mild- moderate:
a) Proctitis and proctosigmoiditis:
1. Topic ASA (mesalazine)
2. Oral ASA (mesalazine)
3. Consider adding oral prednisolone
b) left sided or extensive disease:
1. High dose oral ASA (mesalazine) (passmed say + topical ASA)
2. Consider adding oral prednisolone

Severe:
1. IV corticosteroids (if contraindicated or not tolerated, use IV ciclosporin).
2. IV ciclosporin or consider surgery (if IV ciclosporin contraindicated or not tolerated, consider infliximab).

(Indications for emergency surgery:
Surgery should be considered in patients with:
- Acute fulminant ulcerative colitis
- Toxic megacolon who have little improvement after 48-72 hours of intravenous steroids
- Symptoms worsening despite intravenous steroids)

Maintain remission:
Mild- moderate:
a) proctitis and proctosigmoiditis:
1. Topic or oral mesalazine
b) left sided or extensive disease:
1. oral mesalazine

Severe or >=2 exacerbations in the past year:
1. oral azathioprine or oral mercaptopurine

Question 20

What complications may arise from ulcerative colitis?

Answer 20

1. colonic adenocarcinoma
2. toxic megacolon (urgent decompression of the bowel in the form of a nasogastric tube)
3. primary sclerosing cholangitis
   - (PSC ⇒ inflammation and fibrosis of intra and extra-hepatic bile ducts.
   - UC + Cholestasis (ie. jaundice and pruritus. Raised ALP and GGT).
   - ERCP/MRCP can be used to diagnose, showing ‘beaded’ appearance of biliary structures.
   - ERCP provides clear imaging of the bilary tree but it is invasive
   - Associated with p-ANCA and ASMA.
   - Can lead to cholangiocarcinoma (PSC is main risk factor for cholangiocarcinoma, raised CA19-9 levels).)
   - Cholangiocarcinoma = bile duct cancer.