pseudomembranous colitis

see also:

• Clostridium difficile
• colitis

• a form of generally diffuse colitis resulting from antibiotic-induced overgrowth of Clostridium difficile (although other bacteria may also cause this picture such as Staph. aureus, Salmonella, etc) in the large bowel which results in a potentially life threatening colitis as a result of the production of two toxins which damage the mucosa and cause necrosis and inflammation
• accounts for 20% of antibiotic-related diarrhoea
• it was first described as a complication of C. difficile infection in 1978

• usually occurs within 3-9 days of starting antibiotics but may occur much later, even weeks after ceasing antibiotics

• any antibiotic can cause it, but especially broad spectrum beta lactams (penicillins, cephalosporins) or clindamycin
• elderly
• hospitalisation
• presence of a virulent strain in the hospital
• poor hand hygiene (spores are spread from faeces to surfaces to hands of healthcare workers)
• inadequate cleaning of hospital rooms on discharge of patient
• past GIT surgery
• gastric acid suppression such as proton pump inhibitors (PPIs) or H2-type antihistamines
• renal impairment
• prolonged elemental diet (lacking in protein)
• immunocompromised

• usually present with diarrhoea which is usually profuse, watery/mucoid and foul smelling (horse manure smell), and may contain blood or pseudomembranes
• may then develop:
  • abdominal pains
  • fevers
  • electrolyte disturbances and dehydration
  • sepsis / septicaemia and septic shock
  • bowel perforation
  • toxic megacolon
  • lower GIT bleeding
  • rarely, oligoarthritis and iridocyclitis

• suspect if new onset of more than three partially formed or watery stools per 24-hour period whilst on, or had recent antibiotics, especially if in hospital, and especially if develops abdominal pain and fever
• urgent stool C.Diff PCR
  • may need repeating as not 100% sensitive

• supportive care
• IV rehydration may be required
• contact precautions as per gastroenteritis
• look for markers of severe disease:
  • T > 38.3 deg C
  • serum albumin < 25 g/L
  • peripheral WCC > 15,000 cells/microL
  • deteriorating renal function
  • elevated serum lactate
  • toxic megacolon
• oral metronidazole tds
  • or oral qid vancomycin with cholestyramine (binds the two toxins) may be used in severe cases
• +/- faecal / stool transplant
• patients with severe disease will require iv antibiotic Rx and may require ICU care