Antibiotics, if the patient has any of the factors associated with severe disease.
Emergent surgical consultation for:
Peritoneal signs
Pneumatosis coli
Portal venous gas
Pan-colonic distribution, or
Isolated right-colon<unk>  on imaging
Peritoneal signs
Pneumatosis coli
Portal venous gas
Pan-colonic distribution, or
Isolated right-colon<unk>  on imaging
Ischemic colitis
Infectious colitis
Ulcerative colitis
Stercoral colitis
Diverticulitis
CMV colitis
Crohn's colitis
Diverticulosis