The best choice of treatment for acute colonic diverticulitis with purulent peritonitis is uncertain.

Severe stages of acute, colonic diverticulitis can progress into intestinal perforations with peritonitis. In such cases, urgent treatment is needed, and Hartmann's procedure is the standard treatment for cases with fecal peritonitis. Peritoneal lavage may be an alternative to resection for acute diverticulitis with purulent peritonitis, but ongoing randomized trials are awaited to clarify this.