Toxic megacolon
= colonic dilation (>6cm) with systemic toxicity, usually due to a acute colitis of different causes. It can involved the whole colon or only one segment.
Causes:
Clostridium difficile pseudomembranous colitis
Other infections – Salmonella, Shigella, Entamoeba
Ulcerative colitis
Crohn’s disease
Ischaemic colitis
The patient usually presents with abdominal pain / abdominal distension, fever, bloody diarrhoea and often have signs of shock. On the abdominal Xray or CT scan there are signs of colonic dilation (diameter > 6cm, loss of haustra).
It can be complicated by perforation and / or sepsis / septic shock.
Mortality is very high, especially for cases that do not respond to conservative management.
Treatment is initially conservative, but if there is no response in 24 – 72 hours they normally proceed to surgical intervention/ colectomy.
Conservative management includes:
– aggressive fluid resuscitation +/- vasopressor support
– iv antibiotics (broad spectrum)
– keep the patient nil by mouth and NG tube for bowel decompression
– avoid medications that reducing GI motility (opiates)