Ulcerative Colitis


UC is a chronic, relapsing-remitting, non-infectious inflammatory disease of the GI tract, involving the rectum and variable lengths of colon.

  • Unlike Crohn’s disease, inflammation is usually only superficial, affecting the mucosal layer.
  • UC can be broadly classified by the extent of disease
    • Ulcerative proctitis
      • Inflammation of the rectum only
    • Left sided colitis
      • inflammation extends to the sigmoid colon but not beyond the splenic flexure
    • Extensive colitis (pancolitis)
      • inflammation extends beyond the splenic flexure

Aetiology/Risk factors

  • The exact cause of UC is unknown
  • Genetic
    • Genetically susceptible individuals- abnormally reactive humoral and cell mediated immunity against intestinal bacteria
    • Family history is a strong risk factor
    • HLA-B27 allele is associated with UC, Ankylosing spondylitis, psoriatic arthritis, uveitis and other spondyloarthropathies
  • Autoantibodies e.g. perinuclear antineutrophil cytoplasmic antibodies (p-ANCA) may play a role
  • Smoking, in contrast to Crohn’s, is protective against UC
  • NSAID use may increase the risk of UC and Crohn’s


Onset of symptoms is usually (but not always) insidious/slow.

  • Bloody diarrhoea for more than 6 weeks is a cardinal feature
    • Urgency and nocturnal diarrhoea also common
    • Tenesmus (persistent painful urge to pass stool even when rectum is empty)
  • Abdominal pain
    • Colicky
    • Lower left quadrant
    • May be relieved by bowel movements
  • Weight loss, anorexia
  • Extraintestinal manifestations (see Crohn’s disease)
    • Psoriasis/psoriatic arthritis and ankylosing spondylitis are more common in patients with UC (HLA B27 allele association)


  • Initial Blood investigations
    • FBC- anaemia (chronic disease, blood loss); thrombocytopenia
    • U&Es- Hypokalaemia, hyponatraemia, hypomagnesemia
    • LFTs- Hypoalbuminaemia
      • Also check for extraintestinal manifestations e.g. raised Alk Phos/bilirubin (may suggest hepatobiliary disease)
    • Raised CRP (correlates with disease activity)
    • Serology
      • p-ANCA is positive in 60-80% of patients with UC (50% sensitive and 94% specific)
      • ASCA less common in UC (moreso in Crohn’s)
  • The gold standard for the diagnosis of UC is colonoscopy with biopsy
    • abnormal erythematous mucosa (superficial ulceration may be present; deep ulceration rare cf Crohns) extending from the rectum to part or all of the colon
      • the inflammation is uniform, without normal mucosa in between (skip lesions are not a feature of UC but of Crohns)
      • histologically, inflammation is limited to the mucosa/submucosa (cf Crohns).  Crypt abscesses/atrophy is classical but not specific.  Infiltration with inflammatory cells (mainly neutrophils (acute activity)/lymphocytes (chronic), plasma cells, mast cells and eosinophils)
  • Imaging may be useful in evaluating the extent of disease
    • Contrast enema studies traditionally most useful but CT colonography becoming increasingly popular

Assessing Severity

  • Truelove and Witts’ severity index
  • jfiodjvodf

NB Subacute UC refers to moderate-severely active UC that would be managed in an outpatient setting


  • Inducing remission
    • Mild – moderate (/ first presentation)- 1st line
      • Proctitis/proctosigmoiditis
        • offer topical aminosalicylate alone or combined oral and topical aminosalicylate
        • Oral aminosalicylate may be used alone but is not as effective
          • if this is not suitable a topical / oral corticosteroid may be offered
        • Subacute disease may be offered oral prednisolone
      • Left-sided and extensive disease
        • high induction dose of oral aminosalicylate
        • consider a topical aminosalicylate or oral beclometasone diproprionate
          • if these aren’t appropriate, consider oral prednisolone
      • 2nd/3rd line – any extent
        • add oral prednisolone (stop beclometasone treatment prior to this)
        • consider adding oral tacrolimus to prednisolone if this is inadequate
        • NB Infliximab is NOT recommended for mild-moderate disease)
    • Acute Severe disease; all extents
      • Offer IV corticosteroids
        • Where this is not tolerable or contrainidicated- consider IV ciclosporin (or surgery)
      • Assess need for surgery
        • more likely if >8 stools/day; pyrexic; tachycardic; colonic dilation on AXR
  • Maintaining remission
    • For 1st time, or after mild-moderate disease
      • Proctitis/proctosigmoiditis
        • Topical +/- oral aminosalicylate (daily or intermittent)
      • Left sided/extensive disease
    • For 2+ flare-ups in 12 months, if remission is not maintained with oral aminosalicylates, or after a severe flare up:
  • Other management issues
    • Screen and monitor for osteopenia/osteoporosis
    • Regular colonoscopy for colorectal cancer screening (as well as disease activity)

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