What is the underlying pathology of pseudomembranous colitis?
Clostridium difficile is a gram-positive anaerobe which is not a normal bowel commensal, but rather colonises the bowel after the normal colonic biology has been disrupted (e.g. antibiotics or chemotherapy). C. difficile produces two toxins (A and B) which have both cytotoxic and enterotoxic effects on the bowel. Clinical manifestation is thought to be predominantly due to toxin B.
What is the usual treatment of pseudomembranous colitis?
Treatment involves supportive therapy (fluid and electrolyte replacement) and eradication of C. difficile with antibiotics (usually vancomycin or metronidazole).
A particularly gross treatment has also been employed, one which I think most people would conceptually struggle with. Do you know what I am talking about?
A novel, if somewhat disturbing, treatment option is that of faecal transplant, whereby 'healthy' faecal matter is either administered via nasogastic tube or directly into the colon, after having been donated by a family member.
What incidental findings are present in the region of the pancreatic head?
Dilated common bile duct and a medially projecting duodenal diverticulum (see annotated images)
The majority of the large bowel, from approximately the hepatic flexure down to the anus, is thick-walled with enhancing mucosa and minor pericolic fat stranding. The lumen is fluid-filled and only mildly distended, particularly distally. There is no free intra-abdominal fluid or gas. No mesenteric gas or portal gas.
Incidental note is made of a prominent common bile duct and a duodenal diverticulum.