Sclerosing encapsulating peritonitis

Case contributed by Dr Rupesh Namdev


Severe abdominal pain on and off for 6 months. Constipation, vomiting and anorexia. Clinically, a partially mobile mass is palpable in lower abdomen

Patient Data

Age: 66 years
Gender: Male

At the mid / lower abdomen in the midline, there is grouping of small bowel loops, mainly the distal jejunal, ileal loops. These are encapsulated by a thick enhancing fibrous membrane. The bowel loops within the lesion show minimal wall thickening and surrounding fat stranding. Proximal ileal loops fill with contrast but distal ileal loops are air-filled and show no oral contrast filling.

Mesenteric vessels are seen at the center of this ‘mass’ with bowel loops at periphery. There is a prominent loculated fluid collection around the bowel loops within the encapsulated membrane at the left anterolateral aspect. Stomach, duodenum and proximal jejunal loops appear slightly dilated. The distal ileal loops are collapsed and show no oral contrast filling. Rectal contrast is seen filling the colonic loops and reaching up to the ileocecal junction.

Final diagnosis:

Sclerosing encapsulating peritonitis or abdominal cocoon.

Intraoperatively, a whitish thick fibrous capsule was revealed which is encasing the distal jejunal and proximal ileal loops. Interloop adhesions and mild fluid was seen between these encapsulated bowel loops. Membrane dissection and extensive adhesiolysis was performed..

Case Discussion

Sclerosing encapsulating peritonitis or abdominal cocoon is a rare cause of small bowel obstruction characterized by formation of a thick walled sac or "cocoon". The wall of this cocoon is a thick fibrotic membrane and it contains small bowel loops, mesentery and some fluid. Internal adhesions are inevitable. Earlier it used to be an incidental or unsuspected finding during laparotomy but can be diagnosed pre-operatively with high degree of suspicion.


  • idiopathic: usually seen in adolescent females or young adults, usually in tropical and subtropical countries
  • secondary: following tuberculosis, widespread peritonitis, intestinal perforation, prior abdominal surgery or ambulatory peritoneal dialysis for long duration


It is characterized by formation of a thick fibrotic membrane, encasing adherent small bowel loops and forming a sac or cocoon like mass. This is results in small bowel obstruction.


  • palpable abdominal mass
  • acute or subacute small bowel obstruction
  • weight loss, nausea, vomting and anorexia


Surgery is the treatment of choice and involves membrane dissection and adhesiolysis. Resection of non viable bowel loop can be done.

For a complete discussion on this topic please see: sclerosing encapsulating peritonitis.

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Case information

rID: 27659
Published: 15th Feb 2014
Last edited: 14th Aug 2019
Tag: photo
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