Irritable bowel syndrome (IBS) & Inflammatory bowel disease (IBD)

Question 1

Describe the symptoms that may suggest a diagnosis of Irritable bowel syndrome (IBS)

Answer 1

• In the the preceding 12 months there should be at least 12 consecutive weeks of abdominal discomfort or pain, with 2/3 of the following features:
  
  • Relieved with defecation
  • Onset associated with a change in frequency of stool
  • Onset associated with a change in form of stool
• Other symptoms:
  
  • Bloating
  • Passage of mucus
  • Stool passage symptoms (tenesmus, feelings of incomplete evacuation)
  • Associated gynaecological symptoms (dysmenorrhoea [painful periods]/dyspareunia [pain with sex]), urinary symptoms (frequency, urgency, nocturia) or back pain

It has prevalence of around 10-20%, with F:M >2:1, and onset before 40 years

Question 2

What is irritable bowel syndrome (IBS)?

Answer 2

IBS is a mixed group of abdominal symptoms for which no organic cause can be found. There may be differences in the ‘brain-gut’ axis, leading to increased visceral perception and decreased visceral pain threshold.

Question 3

Describe the epidemiology and risk factors for Crohn’s disease

Answer 3

• Prevalence of 50/100,00
• Male=Female
• Incidence peaks at 15-30, and also again in the 60s

Risk factors:

• Poor diet
• Family history
• Smoking
• Altered immune states

Question 4

Describe the morphology and pathology of Crohn’s disease

I.e where in the body is affected? It appearance?

Answer 4

• Inflammation can affect any part of the GI tract (mouth to anus)
  
  • Most commonly terminal ileum and ascending colon
• Can affect just one area, or multiple areas leaving normal bowel in between
  
  • Skip lesions
• Involved bowel is narrowed due to the thickened wall, with deep ulcers
  
  • ‘Rose-thorn ulcers’
  • ‘Cobblestone’ appearance on CT (specific to Crohn’s, not seen on XR)
• Inflammation extends through all layers of the bowel
  
  • Fistulae and stenosis are common

Question 5

What are the clinical features of Crohn’s disease?

Answer 5

• Abdominal pain (varying character)
• Diarrhoea (steatorrhoea in ileal disease, bloody in colonic disease)
• Weight loss (or failure to thrive -FTT)
• Sever apthous ulceration of the mouth (early sign)
• Anal complications (fissure, fistula, haemorrhoids, skin tags, abscesses)
• Extra GI manifestations
• Can present with acute RIG pain/mass

Question 6

Describe the epidemiology for ulcerative colitis

Answer 6

• Affects 100-200/100,000, again with a peak at 15-30 and also around 60
• Smoking is protective
• Females>Males

Question 7

Describe the morphology and pathology of ulcerative colitis

I.e where in the body is affected? It appearance?

Answer 7

• Inflammation that starts in the rectum, extending proximally along the colon
  
  • Proctitis if affects the rectum alone
• In some patients there can also be inflammation of the distal terminal ileum
  
  • Backwash ileitis
• The inflammation only affects the mucosa, which is excessively ulcerated
  
  • Gives adjacent mucosa the appearance of inflammatory polyps

Question 8

What are the clincal features of Ulcerative colitis?

Answer 8

• Crampy lower abdominal discomfort
• Gradual onset diarrjoea (often bloody)
• Urgency and tenesmus if disease confined to the rectum
• Extra-GI symptoms

Question 9

Give an overview of how the Crohn’s and Ulcerative differ histologically

Answer 9

• Crohn’s: transmural inflammation, lymphoid hyperplasia and granulomas
• UC: muscosal inflammation, crypt abscesses and goblet cell depletion

Question 10

Crohn’s

Ulcerative Colitis

Location

Anal involvement

Continuity

Fistulae

Histology

Smoking

Cure

Answer 10

Crohn’s

Ulcerative Colitis

Location

Mouth to anus

Colon only

Anal involvement

Often

Seldom

Continuity

Discontinuous ‘skip lesions’

Continuous from rectum

Fistulae

Common

Uncommon

Histology

Transmural inflammation, granulomas,

goblet cells present

Mucosal inflammation only, crypt abscesses,

goblet cell depletion

Smoking

Increases risk

Protective

Cure

Surgery less effective (skip lesions)

Cured by colectomy

Question 11

What are extra-colonic (outside of the colon) manifestations of inflammatory bowel disease (IBD) - crohn’s and UC

Answer 11

• Eye disorders such as conjunctivitis and uveitis may occur in 5% of IBD patients
• Seronegative arthritis of the spine and peripheral joints occurs in 15% of IBD patients
• Sclerosing cholangitis and cholangiocarcinoma have a strong relationship with UC (but not Crohn’s)
• Erythema nodosum and pyoderma gangrenosum may be found in IBD patients.

Question 12

What investigations would you do for a patient with suspected inflammatory bowel disease?

Answer 12

• Bloods:
  
  • FBC, U&Es, CRP/ESR, LFT
  • Serum iron/B₁₂/folate if anaemia
• Stool studies
  
  • Stool chart
  • Microscopy x3 to exclude infective causes
  • Calprotectin (may be ordered to rule out IBD n general practice)
• Radiology
  
  • AXR/CXR in acute disease
  • CT in Crohn’s - to look for complications
• Endoscopy
  
  • Rigid/flexi sigmoidoscopy in UC
  • Colonoscopy
  • Endoscopic rectal biopsy may be taken

Question 13

What operative procedures are used to treat IBD?

When and why are they preformed?

Answer 13

• UC
  
  • surgery may be required if medical treatment does not control symptoms, if local complications such as toxic megacolon and perforation appear, and if disease length necessitates removal because of cancer risk
  • A panproctocolectomy and ileostomy are performed, leaving an ileal spout (toxic, raised from skin, RIF).
• Crohn’s
  
  • Surgery is used in treatment of complications: strictures, adhesions and obstruction
  • Removal of bowel may be performed, with an ileorectal anastomosis
  • If the rectum is involved, panproctocolectomy with ileostomy is an option
  • Surgical treatment of abscess, fissures and fistulae is routine