A review of the spectrum of illness associated with pneumatosis intestinalis enables us to identify the probable causes of, the best diagnostic approaches to, and the most appropriate treatments for this condition. A review of all published material in the English language regarding pneumatosis intestinalis was conducted using the PubMed and MEDLINE databases. Any relevant work referenced in those articles and not previously found or published before the limit of the search engine was also retrieved and reviewed. There were no exclusion criteria for published information relevant to the topic. All of the studies cited in the present review make a point that contributes to the portrayal of this condition. In circumstances in which the same point was made in several different studies, not all were cited herein. All published material on pneumatosis intestinalis was considered. Information was extracted for preferentially selected ideas and theories supported in multiple studies. The collected information was organized by theory. Mucosal integrity, intraluminal pressure, bacterial flora, and intraluminal gas all interact in the formation of pneumatosis intestinalis. Radiography and computed tomography are the best diagnostic tests. Nonoperative management should be pursued in most patients, and underlying illnesses should be treated. When acute complications appear, such as perforation, peritonitis, and necrotic bowel, surgery is indicated.