Differentiating Large Bowel Obstruction from Small Bowel Obstruction

1. Specialists Without Borders Seminar in Surgery Rwanda, September 2010 Differentiating Large Bowel Obstruction fromSmall Bowel Obstruction David Birks FRACS September 2010

3. Differentiating large bowel obstruction from small bowel obstruction Objectives • Physiology & anatomy of small/large bowel • Causes of bowel obstruction • Symptoms & signs • Investigations (plain xray) • Complications • Management – conservative & operative

4. Functions of intestine • Small intestine – absorption of fluid, food, vitamins • Large intestine – absorption of water & Na - converts 1000-2000ml into 200ml semisolid faeces

5. Fluid replacement - GI loss • Type

6. Fluid replacement - GI loss • Type

12. Causes of small bowel obstruction • adhesions (previous operation) • external hernia • small bowel volvulus (primary) • neoplasms • miscellaneous

13. Causes of large bowel obstruction • carcinoma of colon • volvulus (sigmoid) • diverticular disease • miscellaneous

14. Symptoms of bowel obstruction • abdominal pain • vomiting • distension • constipation (no flatus)

15. High small bowel obstruction • frequent, profuse vomiting • central abdo pain • minimal distension

16. Lower small bowel obstruction • colic pain • moderate vomiting ( may be faeculent) • moderate distension

17. Large bowel obstruction • abdominal distension • constipation • lower abdo pain ( may be minimal) • minimal vomiting

19. Physical Examination • abdo scars • external hernia • signs strangulation (tenderness, fever, mass)

21. Investigations • Plain Xray – supine - erect - chest • Hb, WCC, Urea & Electrolytes

22. Further investigations • CT abdomen • contrast study (via NG )

23. Plain x ray SBO • dilated loops with gas • centrally placed • transverse lines (circular folds)

24. Plain x ray LBO • dilated bowel with gas (caecum) • peripheral • haustra (not lines across bowel) • may have cut-off point

27. SBO

28. Supine LBO

30. Prone Carcinoma of Sigmoid – LBO – Decompressed into SB

38. Complications of bowel obstruction • fluid & electrolyte loss - small bowel • aspiration – small bowel • respiratory restriction– large bowel • strangulation – small bowel • caecal perforation – large bowel (competent Ileo-caecal valve)

40. Management of bowel obstruction • nil orally • IV fluid & electrolyte replacement • NasoGastric drainage (small bowel)

41. Operation for bowel obstruction • external hernia (SBO) – emergency • signs of strangulation – emergency • SBO not settling – within 24-48 hr • LBO due to carcinoma - soon

42. Non-operative treatment of bowel obstruction • sigmoid volvulus – decompress via sigmoidoscope • post-operative SBO • intussusception in infants (2/12 – 2 yr) • previous operations for SBO • radiation • abdominal carcinomatosis

43. Operation - SBO • midline incision look for ileo-caecal valve • treat cause • external hernia – incision over hernia - if gangrene convert to midline

44. Operation - LBO • midline and resect bowel pathology +/- anastomosis +/- stoma • if left sided obstruction – transverse colostomy through right upper trans incision

47. Summary of bowel obstruction • Physiology & anatomy of small/large bowel • Causes of bowel obstruction • Symptoms & signs • Investigations (plain xray) • Complications • Management – conservative & operative

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