Inflammatory bowel disease

 

 

Aetiology

Environmental trigger to genetic predisposition

Dietary or bacterial antigens

Smoking

Infection

Immunological

 

Pathology

Crohn`s - any part of GI tract - mostly terminal ileum

Colitis - only the colon

Activation of macrophages, lymphocytes and polymorphonuclear cells

Intestinal wall is infiltrated with acute and chronic inflammatory cells.

 

Features

Inflammation and ulceration, relapsing and remitting

Onset usually in young adult life

 

Complications

Severe, life-threatening inflammation of the colon causing toxic megacolon, bacterial toxing freely move into the blood.

Abscesses, perforation, bleeding possible life threatening haemorrhage, carcinoma risk is highest in colitis.

 

Crohn`s

Presentation 10 - 40 years of age

Diarrhoea, abdominal pain, weight loss, malaise, anorexia, nausea

 

Principle features of Crohn`s

Diarrhoea

Weight loss

Abdominal pain

Fistulas between two loops of affected bowel or bladder or vagina,

 

Colitis

Usually presents between 20 - 40 years

Diarrhoea 10 - 20 liquid stools per day

Blood and mucus

Sometimes lower abdominal pain

 

Principle features of Colitis

Diarrhoea with blood and mucus

High bowel opening frequency

Lower abdominal discomfort

Invariably involves the rectum (proctitis)

Often involves the sigmoid and left side of the colon

Sometimes involves whole colon

 

Treatment - remember these are life threatening conditions

 

Crohn`s

Symptomatic e.g. prevent diarrhoea

Treat anaemia

Acute attacks - corticosteroids 30 - 60 mg/day

Immunosuppressive agents e.g. azothioprine, ciclosporin

Aminosalicylates

Surgical

 

Colitis

Sulphasalazine

Local anti-inflammatory and steroids

Oral steroids, prednisolone

Immunosuppressive agents e.g. ciclosporin

Surgical

 

 

 

 

 

 

 

 

Crohn`s disease

 

Pathology

A segmental transmural inflammation of the intestines Any area of the GI tract

Mostly found in the distal ileum and sometimes right colon Skip lesions

May involve extraintestinal tissues

Oedematous reddened terminal ilium on laparotomy

 

Pathophysiology

Inflammation

Immune mediated inflammation

Cytotoxic T cells sensitised to intestinal bacteria

 

Aetiology

Strong genetic susceptibility

Probably chromosome 16, centromeric region

Mycobacteria or Pseudomonas is a possibility

Nature of flora

Mild link with smoking

 

Activation of macrophages, lymphocytes and polymorphonuclear cells with release of inflammatory mediators.

 

Epidemiology

Occurs throughout the world

Incidence is 0.5 5 per 100 000

Incidence has probably increased over past 30 years

More common in Europeans, Jews and females

 

Principle features of Crohn`s

Diarrhoea with colicky abdominal pain (75-80% of cases)

Recurrent fever (15-50% of cases)

Weight loss

Blood in stools usually

Right lower quadrant pain and tenderness (may mimic appendicitis)

Possible right lower quadrent mass swelling or abscess

Possible chronic bleeding

Presents in adolescents or young adult life

Diarrhoea.

Malaise, anorexia, nausea, lethargy

A pattern of relapses

Severity varies significantly between cases

Insidious or acute presentations

Steatorrhoea in small bowel disease

Anal and perianal disease in 25% of cases often preceding large and small bowel features by years

Ulceration of mouth is often seen

 

Complications

Perforation Obstruction

Fistula with other areas of bowel, bladder, vagina Inflammation of whole thickness of gut wall

Visceral peritoneum may be inflamed leading to adhesions

3 fold increased risk of small and colorectal carcinoma

Anaemia

 

Investigations

Anaemia, usually normochromic, normocytic ESR, CRP and WCC all raised

Hypoalbuminaemia Liver biochemistry may be abnormal

Saccharomyces antibodies usually present Stool cultures

Barium follow through

Ultrasound and CT

 

Management

Symptomatic e.g. prevent diarrhoea

Surgery for obstruction, abscess or fistula.

Surgical bypass a faecal stream factor

Treat anaemia

Enteral nutrition, low fat, low linoleic acid

Acute attacks - corticosteroids 30 - 60 mg/day

Immunosuppressive agents e.g. azothioprine, cyclosporine