Pneumatosis cystoides intestinalis (PCI) is a disease characterized by a multiple of gas cysts in the wall of any area in the gastrointestinal tract. It is known to have primary (15%) and secondary (85%) forms. In most of the cases it develops due to an underlying cause like trauma, inflammation, medication use, immunosuppression and neoplasm, autoimmune or pulmonary diseases. A 29-year-old female case, who had lost 15 kg in about one month presented at Fırat Medical Center complaining from severe abdominal pain, nausea and vomiting. Upon observation of free air in the abdomen by radiological examination, the case was pre-diagnosed as rectum perforation, and operated on. Macroscopic examination of the operation material showed a large amount of thin-walled cystic structures filled with air on the ileum serosa. Pneumatosis intestinalis diagnosis was given after histopathological examination.

Although it was rarely seen in acute abdomen instances, the diagnosis of pneumatosis cystoides intestinalis should also be considered.