Left paraduodenal hernias are the most common congenital internal hernia. The defect arises via a failure of the descending mesocolon to fuse with posterior parietal peritoneum. As such intraperitoneal contents can pass posterior to the inferior mesenteric vein and ascending left colic artery. We present a case report of a 41 year old female with prior negative diagnostic laparoscopy 12 years prior to presentation, with 28 hours of epigastric severe pain during her most recent ED visit. Initial imaging workup noted inflammation in the lesser sac, and a mistaken diagnosis of interstitial pancreatitis was made. When her symptoms did not resolve surgery was consulted, and she was taken for diagnostic laparoscopy. A hemorrhagic but non-incarcerated left paraduodenal hernia sac with loops of jejunum was noted. The jejunum was reduced and viable, and the defect was closed with permanent suture laparoscopically. This case serves as a reminder that for rare sources of internal hernia, abdominal CT has historically underperformed. Surgeons and emergency physicians must remain vigilant to detect potentially lethal missed diagnoses when patient's symptoms are incongruent with the present diagnosis.