Pneumoperitoneum is the result of a gastrointestinal (GI) tract perforation in more than 90% of cases. Perforation of the stomach or duodenum caused by peptic ulcer is considered the most common cause of pneumoperitoneum. In this article, we present a case of pneumoperitoneum associated with sigmoid colon perforation, which is the result of the patient trying to create a laxative effect by inserting the hose attached to the wash basin into his rectum and opening the water afterwards. An 89 years old male patient was brought to the emergency department with complaints of abdominal pain starting about 2 hours ago. The patient's abdominal ultrasonography showed free fluid up to 10 cm in the lower abdomen. Posterior anterior chest X-ray and direct standing abdominal X-ray of the patient had subdiaphragmatic free air and images with free fluid, pneumoperitoneum and perforation were obtained in contrast enhanced abdominal tomography. As a result of surgery performed by general surgery it was seen approximately 30 cm proximal from the rectumthat there was a 4 cm perforation in the sigmoid colon. We must consider pneumoperitoneum, which is the result of colon perforation especially in elderly patients with acute abdominal pain, to be definitely among our differential diagnoses.