Pneumatosis intestinalis is a rare disorder characterized by gas-filled cysts within the subserosal and/or submucosal regions of the intestinal wall. The source of this gas and its translocation across the mucosa is incompletely understood. Most (85%) cases are associated with medical conditions, ranging from psychiatric through respiratory disorders to gastrointestinal-related diseases; the remaining 15% lack any recognizable cause or association. In this case report, pneumatosis coli (affecting the colon) occurred in a patient following abdominal surgery and was associated with pseudomembranous colitis, which was Clostridium difficile toxin negative-presumably a false negative. Supportive care and appropriate antibacterial agents sufficed to alleviate symptoms and resolve the pneumatosis. Recognizing this uncommon but important association can avoid high financial and personal costs from unnecessary testing and invasive surgical explorations. Consideration should be given to pseudomembranous colitis as the basis for pneumatosis coli developing in patients who have received antibiotics, once gut ischemia has been ruled out.