IBD

• Ulcerative colitis is a chronic, relapse-remitting inflammatory disease that affects the large bowel and rectum
• Ulcerative colitis is the most common form of IBD
• UC causes continuous inflammation starting in the rectum, working its way upwards. Only the superficial mucosa is affected.
• Typical history of UC:

  • Diarrhoea +/- blood +/- mucus (blood is more common in UC than Crohn's)
  • Urgency
  • Tenesmus - frequent urge to open bowels without being able to
  • Lower abdominal pain and bloating
  • Fatigue
  • Weight loss
• Extra-intestinal manifestations of UC:

  • Red eye conditions - uveitis / episcleritis
  • Erythema nodosum
  • Pyoderma gangrenosum
  • Primary sclerosing cholangitis - scarring of bile ducts
  • Anaemia
  • Thromboembolism
• Clinical exam of UC:

  • Digital rectal exam - blood and/or mucus
  • Pallor - anaemia
  • Finger clubbing
• Risk factors for UC:

  • Family history of IBD
  • HLA-B27 positive
  • Recent GI infection
  • NSAIDs
  • Smoking cessation - smoking masks symptoms
• Clinical Investigations for UC:

  • FBC for Hb (anaemia) and platelet count (raised with inflammation)
  • CRP
  • U&Es - electrolyte imbalances and kidney function
  • LFTs - can show low albumin in severe disease
  • TFTs - to rule out hyperthyroidism as cause of diarrhoea
  • Vitamin B12, folate and ferritin
  • Anti-TTG - coeliac disease as a differential
  • Stool microscopy and culture - rule out infection
  • FIT test - blood in stool
  • Faecal calprotectin - 90% sensitive and specific for IBD
• Gold standard investigation for UC is endoscopy with multiple intestinal biopsies. Sigmoidoscopy is usually sufficient, colonoscopy should be avoided in an acute flare due to risk of bowel perforation. Biopsy of UC will show:

  • Macroscopic - continuous inflammation, ulceration and pseudo polyps
  • Microscopic - crypt abscesses and decreased goblet cells
• Plain film abdominal x-ray or CT scan can be used for exclusion of UC complications during an acute presentation - toxic megacolon and perforation
• Management of mild to moderate UC:

  1. Oral/topical or rectal aminosalicylate - mesalazine
  2. Oral azathioprine / mercaptopurine (DMARD)
  3. Corticosteroids (not used to maintain remission)
• Acute severe UC requires hospital admission and IV hydrocortisone. Surgery may be required.
• Patients admitted to hospital for acute IBD need VTE prophylaxis
• Complications of UC:

  • Severe bleeding
  • Perforation
  • Toxic megacolon
  • VTE
  • Colorectal cancer - colonoscopic surveillance
• Crohn's disease is a chronic, relapse-remitting inflammatory disease that affects the whole GI tract from mouth to anus. The inflammation is transmural unlike in ulcerative colitis. There are also skip lesions, unlike in UC where the inflammation is continuous.
• Typical history of Crohn's disease:

  • Right lower quadrant pain - terminal ilium
  • Peri umbilical pain
  • Peri anal pain/itching
  • Oral aphthous ulcers
  • Nausea/vomiting
  • Fever
  • fatigue
  • weight loss
• Extra-intestinal manifestations of Crohn's disease:

  • Arthritis
  • Red eye diseases
  • Erythema nodosum
  • Pyoderma gangrenosum
  • Primary sclerosing cholangitis (more common in UC)
  • Fatty liver disease
  • B12 deficiency
  • Thromboembolism
• Crohn's disease upon clinical exam:

  • Abdominal tenderness/mass
  • Perianal tags, fissures, fistulas or abscess
  • Finger clubbing
  • Aphthous ulcers
• Risk factors for Crohn's disease:

  • Family history of IBD
  • Smoking
  • Previous GI infection
  • NSAIDs
  • High sugar, low fibre diet
• Investigations for Crohn's disease:

  • FBC for Hb (anaemia) and platelet count (raised with inflammation)
  • CRP
  • U&Es - electrolyte imbalances and kidney function
  • LFTs - can show low albumin in severe disease
  • TFTs - to rule out hyperthyroidism as cause of diarrhoea
  • Vitamin B12, folate and ferritin
  • Anti-TTG - coeliac disease as a differential
  • Stool microscopy and culture - rule out infection
  • FIT test - blood in stool
  • Faecal calprotectin - 90% sensitive and specific for IBD
• Colonoscopy with biopsies is the gold standard for diagnosis of Crohn's. OGD can also be done if there is upper GI symptoms. Biopsy shows:

  • Macroscopic - cobblestone appearance, skip lesions, aphthous ulcers
  • Microscopic - transmural involvement and non-caseating granulomas
• MRI in the context of Crohn's disease is used for disease mapping
• Initially, monotherapy is used for inducing remission of Crohn's disease:

  • Corticosteroids
  • Budesonide

  Further medication can be added:

  • Azathioprine / mercaptopurine
  • Methotrexate
  • Biologics
• Maintaining remission in Crohn's disease:

  • Azathioprine/mercaptopurine
  • Methotrexate
• Surgery for Crohn's disease can involve resection of the bowel (colostomy) and treating fistulas or strictures
• Complications of Crohn's disease:

  • Perianal disease
  • Strictures, fistulas, perforation and haemorrhage
  • anaemia
  • Malnutrition
  • Malignancy of small and large intestine
• Steroids in IBD:

  · To induce remission

  · Corticosteroids are strong, non-selective, anti-inflammatory agents

  · They inhibit synthesis and transcription of pro-inflammatory proteins, which down-regulates the production of inflammatory cytokines such as IL-1 and tumour necrosis factor

  · Anti-inflammatory mediators are up-regulated by corticosteroids

  · Prednisolone, dexamethasone

  · Increased appetite, rapid mood swings, thin skin that bruises easily, muscle weakness, immune system suppression, osteoporosis
• Disease modifying agents (DMARDs) in IBD:

  · Methotrexate- inhibits enzyme AICAR transformlylase. Leads to adenosine accumulation which has anti-inflammatory effects.

  · Azathioprine and mercaptopurine- purine (leads to uric acid rise- inflammation) analog that converts to its active metabolites. Then inhibits purine synthesis. Absorbed rapidly through the GI system.

  · Infliximab- binds to TNF-alpha, preventing inflammation.