• Disease of inappropriate activation of gut mucosal immune system
• Driven by normal bowel flora
• ?Defective barrier mechanism

• Genetics
• Smoking
• Diet: low fibre
• Immune mechanisms

• Genetics
• Smoking protective

• Transmural inflammation
• Serositis common

• Mucosal inflammation (with crypt abscesses
• Serosa normal

• Anywhere along GIT (but esp terminal ileum)
• Patchy "skip lesions"
• "Cobblestone" appearance with fissuring
• Strictures common
• Fistulae common

• Starts at rectum and progresses proximally (ileum 10%)
• Continous lesions
• No fissuring
• Strictures uncommon
• Fistulae uncommon

• Non-caseating granuloma (aggregation of macrophages)

• Inflammation - neutrophils, macrophages

• Possible malignant change

• Malignant change well recognised

• Severe acute colitis

1. Frequent stools >6/day
2. Fever, tachcardia
3. Systemically "unwell"
4. Rectal bleeding
5. Low albumin

• Intermittent relapsing colitis
• Chronic persistant colitis
• Asymptomatic

• Skin: Erythema nodosum, pyoderma gangrenosum
• Eyes: iritis
• Joints:

Endoscopic grading

Depends on

1. Site of disease
2. Type of disease
3. Disease severity

Medical treatment

1. 5-ASA (blocks prostaglandins and leukotrienes)
2. Steroids
3. Immunosuppressants - Azathioprine (mercaptopurine derivative), infliximab (anti TNF antibody), methotrexate (antimetabolite)

Indications for sugery

• Limited Resections
• Strictureplasty
• Bypass procedures

1. Elective
   • Chronic symptoms despite medical therapy
   • Malignancy
   • Fistulating disease
   • Chronic obstruction
2. Emergency
   • Clinical: Severe colitis, haemorrhage
   • Biochemical: WCC, CRP
   • Radiographical: Perforation

Depends on

1. Site of disease
2. Type of disease
3. Disease severity

Medical treatment

1. 5-ASA (blocks prostaglandins and leukotrienes)
2. Steroids
3. Immunosuppressants - Azathioprine (mercaptopurine derivative), infliximab (anti TNF antibody), methotrexate (antimetabolite)

Indications for sugery

• Total colectomy + ileostomy + mucous fistula
• Proctocolectomy + ileoanal pouch (depends on adequate anal musculature)
• Types of pouch: S-pouch, J-pouch, Four-loop W-pouch

1. Elective
   • Chronic symptoms despite medical therapy
   • Malignancy
2. Emergency
   
   • Clinical: Severe colitis, haemorrhage
   • Biochemical: WCC, CRP
   • Radiographical: Perforation, toxic megacolon