Pseudomembranous colitis is an inflammatory condition of the colon characterized by elevated yellow-white plaques that coalesce to form pseudomembranes on the mucosa. Patients with the condition commonly present with abdominal pain, diarrhea, fever, and leukocytosis. Because pseudomembranous colitis is often associated with C. difficile infection, stool testing and empiric antibiotic treatment should be initiated when suspected. When results of C. difficile testing are negative and symptoms persist despite escalating empiric treatment, early gastroenterology consultation and lower endoscopy would be the next step in the appropriate clinical setting. If pseudomembranous colitis is confirmed endoscopically, colonic biopsies should be obtained, as histology can offer helpful clues to the underlying diagnosis. The less common non-C. difficile causes of pseudomembranous colitis should be entertained, as a number of etiologies can result in this condition. Examples include Behcet’s disease, collagenous colitis, inflammatory bowel disease, ischemic colitis, other infections organisms (e.g. bacteria, parasites, viruses), and a handful of drugs and toxins. Pinpointing the correct underlying etiology would better direct patient care and disease management. Surgical specialists would be most helpful in colonic perforation, gangrenous colon, or severe disease.