Foreign body ingestion is common in mentally impaired adults. Fortunately, the vast majority of all swallowed objects pass through the gastrointestinal tract uneventfully. For patients in whom conservative treatment fails, early endoscopic intervention is required. Surgery is seldom indicated and reports of perforation or penetration of the GI tract are anecdotal. We present a case of a 32 years old mentally impaired patient with a trans-colonic penetration of a foreign body into the retro-hepatic vena cava.