see also:

• inflammatory bowel disease (IBD)

• annual incidence in USA 1 case per 1000 white adults and rising
• affects all age groups, esp. 3rd & 4th decades of life
• almost exclusive to industrialised nations with urban > rural
• FH UC in 10-15%
• whites 4x risk cf non-whites
• M=F although increased risk if on OCP
• outside the tropics, it is the commonest cause of prolonged bloody diarrhoea
• smokers tend to have higher levels of hydroquinone which allows Streptococcus mitus oral flora take residence in the gut which triggered the emergence of helper Th1 cells which fight against the Th2-immune response and this seems to be a mechanism for their reduced risk of ulcerative colitis ¹⁾
• mutation in the OTUD3 gene may be the cause in some families while others may have OTUD3 dysfunction without mutation
  • 0.1 per cent of people of South Asian descent carried this mutation but not all develop ulcerative colitis

• inflammatory reaction of the mucosa of the colon:
  • always arises 1st in the rectum
  • rectum is only part involved in 10-38% cases
  • pancolitis occurs in 10% cases
  • uniformly continuous disease process with no skip lesions
• mucosal appearance:
  • thick inflammatory exudate of pus, blood, mucus covering irregular shallow ulcers interspersed with islands of swollen mucosa (“pseudopolyps”)
  • increased mucosal friability
  • microscopic “crypt abscesses”
• chronic disease results in colon becoming rigid, foreshortened tube lacking haustral markings

• sacroiliitis, ankylosing spondylitis, cholangitis, hepatitis, hepatitis, amyloid
• colonic Ca

• chronic insidious recurrent abdominal pain, anorexia, weight loss, mild diarrhoea
• acute onset of bloody diarrhoea, abdo. pain, +/- tenesmus, vomiting & fever

• often associated with:
  • emotional stress, infections, other acute illnesses
  • pregnancy, dietary indiscretions, use of cathartics or antibiotics
  • withdrawal of anti-inflammatory or steroid Rx
• extraGIT manifestations may be present in up to 20% cases:
  • peripheral arthritis, apthous ulcers, erythema nodosum, pyoderma gangrenosum

• occurs in 10-15% pts
• parameters suggestive of this:
  • > 6-8 stools per day
  • anaemia - H'crit < 30% (may not be evident until after rehydration)
  • T > 38deg C
  • LOW > 10% of premorbid weight
  • tachycardia
  • erythrocyte sedimentation rate (ESR) > 30
  • se albumin < 30g/L
  • failure of usually effective Rx regimes
  • failure of 5-7 day course of intensive outpatient Rx

• a manifestation of fulminant disease which usually occurs during initial acute episode
• mainly involves transverse colon causing:
  • septic, apathetic, lethargic looking pt
  • high fever, chills, tachycardia
  • progressive abdoinal pain, tenderness & distension
• 25% result in perforation
• precipitants may include:
  • use of anti-diarrhoeal agents
  • vigorous use of cathartics/enemas or barium enema

• 50% occur in pts with fulminant disease without toxic megacolon
• 50% occur in pts with toxic megacolon

• 10% pts

• <1% of patients

• 15% pts
• tend to occur in 1st year of disease & correlate with severity

• risk related to severity & duration of disease esp. over last 10-15 years
• risk appears to be 1% per person per year if have pancolitis
• overall risk 11% after 26yrs

• if acute, non-fulminating disease:
  • colonoscopy (C/I in fulminating disease as risk of perforation) & evaluation of biopsies
• chronic disease:
  • barium enema no longer Ix of choice (C/I in fulminating disease as may cause toxic megacolon or perforation if toxic megacolon is present) but may show:
    • rigid, shortened colon with loss of haustrations & destruction of mucosal pattern ⇒ “hoselike” colon
• if acute, fulminating disease:
  • gentle sigmoidoscopy may be diagnostic as rectum always involved in UC but is indistinguishable from infectious causes
  • plain AXR & erect CXR to exclude:
    • toxic megacolon:
      • transverse colon dilated > 6cm (usually > 8cm)
      • islands of necrotic tissue or gas in the bowel wall may be seen
    • perforation:
      • free gas under diaphragm

• infectious colitis - Campylobacter, Shigella, enterohaemorrhagic E. coli, C. difficile (colitis_pseudomembranous)
• acute ameobiasis - can be difficult to detect in stool, so do serology too
• Crohn's disease - 20% of cases cannot de distinguished histologically or clinically from Crohn's
• in AIDS pts:
  • chronic diarrhoea & diffuse colonic involvement of Kaposi's sarcoma
• in elderly pts in particular:
  • diverticulitis
  • ischaemic colitis
  • radiation colitis
  • carcinoma of colon

• admit any new patient suspected of acute UC for Ix and initial control of disease if confirmed:
• Ix:
  • gentle sigmoidoscopy
  • U&E, FBE, ESR, stool m/c/s ('hot' stool for amoebiasis), serology for amoebiasis
  • AXR, erect CXR
• Mx in ED:
  • inform surgeons/gastro. unit
  • if severe disease then 5 day regime:
    • nil orally
    • IV maintenance fluids
    • twice daily physical examination - inform surgeons of progress
    • record stool frequency & character as well as TPR,BP
    • daily: FBE, U&E, plain XRs, abdo. girth
    • IV hydrocortisone 100mg 6h (reduce dose after a week according to response)
    • hydrocortisone acetate foam enema 125mg x ii/day (reduce after a week prn)
    • IM vitamins
    • consider need for TPN
  • AVOID anti-diarrhoeals (may cause toxic megacolon)
• indications for proctocolectomy & ileostomy (total surgical mortality 2-7%):
  • deteriorating colitis after 5 days
  • toxic megacolon
  • perforation
• less severely ill:
  • steroids po / PR
• maintaining remission:
  • 5-amino-salicylic acid Rx either:
    • sulphasalazine 1g bd po reduces relapse rate by 65%
      • SE: rash, infertility
    • mesalazine 400-800mg tds po is s effective as sulphasalazine but without the sulphonamide side effects

steroids prn

• azathioprine for 6months may reduce need for steroids
  • monitor FBE
• carcinoma surveillance:
• 1-2yrly colonoscopy (more frequent if high grade dysplasia)
• if known UC with mild exacerbations or isolated proctitis then can be Mx as outpatients

• poor if early severe illness or extensive disease