Small Bowel, SBO, IBD

Outline Small bowel physiology

Absorption Barrier

SBO physiology Hyperperistalsis Decreased absorption Increased secretion Clinical aspects

Small Bowel, SBO, IBD

Outline (cont’d) Crohn’s disease

Epidemiology Pathology Indications for operation

Ulcerative colitis Epidemiology Pathology Indications for operation

Small Bowel, SBO, IBD

Small Bowel Physiology Absorbs water, electrolytes, nutrients

Varies between jejunum and ileum Compromised in certain disease states

Requires glutamine as energy source Barrier function

Requires enteral nutrition for maintenance Compromised by lack of feeding ?Leads to nosocomial infection

Small Bowel, SBO, IBD

SBO Physiology Global hyperperistalsis Decreased absorption of H2O & lytes Increased secretion of protein rich fluid Hypoperistalsis in late stages

Small Bowel, SBO, IBD

SBO Physiology Pain and tenderness doesn’t differentiate type Simple SBO

Usually partial Differentiation by plain X-ray or CT May resolve

Strangulated SBO Usually complete Often “closed loop” Requires urgent operation

Crohn’s Disease

Epidemiology Disease of young adults

Peak incidence in late teens and 20’s Smaller peak in 50’s & 60’s

Incidence varies amongst ethnic groups Cause unknown

?Autoimmune ?Infectious ?Genetic

Crohn’s Disease

Pathology Full-thickness involvement Thickened bowel wall and mesentery 50% with non-caseating granulomas May involve any portion of GI tract

Crohn’s Disease

Pathology (cont’d) Ileal involvement most common Colon-only involvement seen Peri-rectal disease common Extra-intestinal manifestations Surgery not curative Malignancy uncommon

Crohn’s Disease

Indications for Operation Abscess Certain fistulae Obstruction Intractability

Crohn’s Disease

Surgical Considerations Important aspect of overall care Bowel conservation important

Limited resection Resect, don’t bypass

Long-term risk of short-gut is low J-pouch not an option in colonic disease

Ulcerative Colitis

Epidemiology Similar to Crohn’s disease Early and late incidence peaks Variable incidence among ethnic groups

Ulcerative Colitis

Pathology Involves only mucosa and submucosa Involves only colon and rectum Serosa normal Normal bowel wall thickness Normal mesentery

Ulcerative Colitis

Pathology (cont’d) Extraintestinal manifestations Malignancy

Duration of disease Extent of disease

Ulcerative Colitis

Presentation Diarrhea, often bloody Abdominal pain Constitutional symptoms Weight loss Fulminant colitis Toxic megacolon

Ulcerative Colitis

Indications for Operation Bleeding (uncommon) Unresponsive fulminant colitis Toxic megacolon Intractability Inability to wean steroids Cancer prevention

Ulcerative Colitis

Surgical Aspects Colectomy curative Total proctocolectomy with ileostomy Ileo-anal pouch pull-through