Complicated diverticulosis.

"Uncomplicated" diverticulitis can be prevented from progressing into "complicated" diverticulitis by early diagnosis and active medical treatment. Complicated diverticulitis develops from a peridiverticular abscess, to a perforation with peritonitis, to fistulation into adjacent viscera, to luminal narrowing by inflammation or stricture formation causing obstruction. Computer tomography (CT) scanning is the diagnostic imaging modality when diverticulitis is suspected and allows percutaneous drainage of peridiverticular abscesses that will enhance the effect of antibiotic therapy with resolution of the acute episode in 75% of patients. Thus, an emergent or urgent operation is converted to an elective operation and a two-stage operative procedure, namely a temporary stoma and a second operation, is avoided. Interventional surgery is urgent for perforation and obstruction. While a Hartmann's resection and temporary colostomy has been the favoured operative procedure, under favourable conditions resection with primary anastomosis is preferable. Although a temporary stoma may be required with primary anastomosis, and hence the procedure is a two-stage one similar to a Hartmann's, the closure of the stoma is less demanding and has a lower morbidity. A single-stage resection and anastomosis is the standard elective treatment for symptomatic fistulas and strictures.