Small bowel obstruction

Small bowel obstruction, abbreviated SBO, is a common pathology managed by general surgeons.

This article gives an overview of SBOs. Its primary focus is benign causes of SBO that have nonspecific pathologic findings.

Specific causes definitively identified by pathology, e.g. adenocarcinoma, or by clinical history/pathology, e.g. Crohn's disease, are dealt with separately.

General

Radiologic/clinical diagnosis.

The usual causes of bowel obstruction (large & small) are (mnemonic) SHAVING:

Strictures (think IBD).
Hernias.
Adhesions.
Volvulus.
Intussusception.
Neoplasia.
Gallstone ileus.

The top three are:^[1]^[2]

Adhesions > hernias > neoplasms.

In the context of bowel obstructions and IBD, pathologists often see resected stomas (that were put in place emergently). These specimens are usually fairly straight forward.

Radiology

Air-fluid levels.

Gross

+/-Adhesions.
+/-Bowel contorted.
+/-Luminal narrowing +/-proximal dilation.
+/-Serosal exudate.
- Suggestive of perforation.

Microscopic

Features:

+/-Adhesions (serosal).
- Dense fibrous tissue replaces the adipose tissue.
- +/-Increased vascularity.
+/-Submucosal fibrosis.
+/-Serositis - seen in small bowel perforation.
+/-Foreign body-type granuloma - due to previous surgical intervention.

DDx:

Small bowel adenocarcinoma - most important differential diagnosis.
Metastatic adenocarcinoma - classically on the serosal aspect.
Signet ring cell carcinoma.

Sign out

SMALL BOWEL, RESECTION:
- SMALL BOWEL WITH FIBROUS ADHESIONS (EXTENSIVE) ASSOCIATED WITH FOCAL LUMINAL
  NARROWING.
- NEGATIVE FOR DYSPLASIA AND NEGATIVE FOR MALIGNANCY.

SMALL BOWEL, RESECTION:
- SMALL BOWEL WITH FIBROUS ADHESIONS (EXTENSIVE), FOCAL LUMINAL NARROWING AND A
  FOREIGN BODY-TYPE GRANULOMA.
- NEGATIVE FOR DYSPLASIA AND NEGATIVE FOR MALIGNANCY.

Ischemic changes

SMALL BOWEL, RESECTION:
- SMALL BOWEL WITH ISCHEMIC CHANGES, FIBROUS ADHESIONS, FOCAL SEROSITIS AND MURAL
  MICROABSCESS FORMATION.
- NO SIGNIFICANT VASCULAR PATHOLOGY APPARENT.
- NEGATIVE FOR MALIGNANCY.

References

↑ URL: http://www.emedicine.com/EMERG/topic66.htm. Accessed on: 19 April 2011.
↑ Greenwald, J.; Heng, M. (2007). Toronto Notes for Medical Students 2007 (2007 ed.). The Toronto Notes Inc. for Medical Students Inc.. pp. GS21. ISBN 978-0968592878.

[1] URL: http://www.emedicine.com/EMERG/topic66.htm. Accessed on: 19 April 2011.

[2] Greenwald, J.; Heng, M. (2007). Toronto Notes for Medical Students 2007 (2007 ed.). The Toronto Notes Inc. for Medical Students Inc.. pp. GS21. ISBN 978-0968592878.

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Small bowel obstruction

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