Solution: The findings on this case are immediately suggestive of a possible colitis with colonic wall thickening and edema. Of particular note are the symmetry of the wall thickening and the distribution (splenic flexure and proximal descending colon). Also, there is relatively little surrounding inflammatory change. This combination of findings suggest a relatively acute ischemic colitis. This likely represents partial mural ischemia considering the lack of portal venous gas and pneumatosis, so the prognosis is likely relatively good and is not likely to require surgery, at least not emergently.