e Abstract—We report a case of a 36-year-old man who was admitted to the Emergency Department with right flank pain. The clinical presentation was suggestive of renal colic. However, a computed tomography scan showed the presence of a foreign body in the inferior duodenal flexure. Upper gastrointestinal endoscopy demonstrated a 6.5-cm wooden toothpick deeply embedded in the duodenal wall; this was removed via endoscopy. The peri-duodenal inflammatory reaction had encased the right ureter, resulting in hydronephrosis. The patient did well and was discharged on post-operative day 7. He did not recall toothpick ingestion. When evaluating patients with acute abdominal pain, foreign body ingestion should be considered. In patients with a history of toothpick ingestion, immediate diagnosis with endoscopic management should be performed. © 2008 Published by Elsevier Inc. e Keywords—foreign body ingestion; duodenal perforation; toothpick INTRODUCTION Most foreign bodies pass through the intestinal tract uneventfully. However, if the objects are sharp like toothpicks, the risk of complications is high. Toothpick ingestion may cause severe, sometimes fatal, internal injuries due to gastrointestinal perforation and migration to neighboring structures. Unfortunately, imaging studies are usually inadequate to detect ingested toothpicks, and endoscopy, laparoscopy, or laparotomy is frequently necessary. We report a case in which toothpick migration through the duodenal wall caused a peri-duodenal reactive inflammation, which lead to right ureteral stenosis and subsequent hydronephrosis. CASE REPORT A 36-year-old man presented to the Emergency Department (ED) with right flank pain. The patient had been well until 3 days before admission, when he began to have pain in the right abdominal quadrants that radiated to the back. The pain did not correlate with food consumption and did not wake him up during the night. There was no hematuria, dysuria, or frequency. He reported nausea and denied having a fever. He had normal bowel movements the day before. The past medical history was significant for gastritis and gastroesophageal reflux disease for which he was on omeprazole 20 mg per day for the previous 2 months. He denied any history of excessive alcohol consumption or illicit drug use. His medical history was otherwise unremarkable