Background: Sclerosing Encapsulating Peritonitis (SEP), also known as abdominal cocoon, is a rare chronic inflammatory condition characterized by encasement of bowel loops within a thick fibro-collagenous membrane. It may be idiopathic or secondary to known risk factors such as peritoneal dialysis, infections, or abdominal surgeries. Due to its rarity and non-specific symptoms, SEP is frequently misdiagnosed, often recognized only intraoperatively. Case Report: We report a case of a 76-year-old male with no prior medical or surgical history, who presented in 2022 and again in 2023 with recurrent episodes of abdominal pain, vomiting, and constipation. Initial conservative management provided temporary relief, but symptoms recurred. Imaging suggested small bowel obstruction with clumped bowel loops. Exploratory laparotomy revealed a dense fibrous membrane encasing the intestines, consistent with SEP. Histopathology confirmed chronic inflammation without evidence of secondary causes. Postoperatively, the patient developed paralytic ileus, which was managed conservatively with nutritional support. He was discharged in stable condition and remained well at follow-up. Conclusion: This case highlights the importance of considering idiopathic SEP in the differential diagnosis of unexplained intestinal obstruction, especially in patients without identifiable risk factors. Early surgical intervention can be curative, though postoperative complications like ileus may prolong recovery.