A 65-year-old man with benign prostatic hyperplasia presented with abdominal fullness and constipation for one week. He did not report any nausea, vomiting or abdominal pain but he mentioned having decreased urine output for the past few days. He recalled that he took some over-the-counter medication for common cold last week. Physical examination revealed a rounded, non-pulsatile mass, more than 15 cm in size, over the lower abdomen with dullness on percussion. Abdominal radiograph showed a huge, ‘full moon’ shadow in the lower abdomen, with severe compression of the adjacent colon (Fig. 1).