Gastroenterology Notes

GASTROENTEROLOGY

Contents:

GI

• Coeliac disease

• Diverticular disease

• Gastro-oesophageal reflux disease

• Inflammatory bowel disease

• Irritable bowel syndrome

Hepatobiliary

• Autoimmune hepatitis

• Cirrhosis

Pancreas

• Acute pancreatitis

To view pictures, just hit the link!

GI

COELIAC DISEASE

Summary Points

• Coeliac disease is a genetically determined chronically inflammatory small bowel disorder of gluten intolerance.

• Patients typically feel bloated, have an altered bowel habit and lose weight

• It is diagnosed by a positive transglutaminase test and a jejunal or duodenal biopsy for confirmation

• It is managed by a gluten free diet

Aetiology and Pathophysiology

T-cell mediated autoimmune disease of small bowel causing a prolamin (alcohol-soluble proteins in wheat, barley, rye, and sometimes oats) intolerance. This leads to villous atrophy and malabsorption which can have a number of secondary complications.

Associated with HLA DQ2 in 95% and DQ8 for 5%, so often see a familial link.

Gluten intolerance varies person to person (i.e. some can tolerate oats).

Epidemiology and Associated Risk Factors

Affects between 1/100 and 1/500 in the UK though a large number are undiagnosed.

Occurs at any age – peak incidences are during infancy and 50-60yrs, mostly an adult presentation.

Risk factors:

• Males

• Family history

• Dermatitis herpetiformis (a bumpy, itchy, blistered eruption)

• Diabetes mellitus

• Hashimoto’s thyroiditis

• IBS

• Down’s Syndrome

• Osteoporosis

• Subfertility

• Irish, Punjabi and South Asian descent

Presentation

50% are asymptomatic. Presentation can vary by age:

Babies and young children:

• Failure to thrive – weight loss and malabsorption

• GI – diarrhoea, vomiting, pale stools (steatorrhoea), constipation

• Irritability, anorexia/off feeds

• Abdo may protrude w/ everted umbilicus.

Older children and adults:

• GI – nausea, vomiting, steatorrhoea, abdo pain/discomfort, bloating, weight loss

• Fatigue, weakness and arthralgia

• Mouth and peri-oral: aphthous ulcers and angular stomatitis (irritation and inflammation around sides of mouth)

• Secondary to malabsorption - Vit D deficiency – osteomalacia; Vit K deficiency - bleeding problems

Assessment

- O/E –

• In infants and young children, their abdomen may protrude w/ an everted umbilicus

• In older children and adults:

  • Dermatitis herpetiformis – picture: http://www.mybwmc.org/library/2/2791

- Ix –

Blood:

• Serum IgA anti-tissue transglutaminase antibodies preferred - false negs in 0.4% population due to IgA deficiency

• Endomysial antibodies if tTGA test unavailable or inconclusive. Both tests are highly specific and sensitive.

Antibodies undetectable 6-12m after start of gluten free diet - can be used to monitor management.

If +ve serological test -> distal duodenal/jejunal biopsy for confirmation - shows villous atrophy, lymphocytic infiltration of hypertrophic crypts and shallow gastric pits (as seen in picture below).

FBC - Iron deficiency anaemia 50% pts

LFTs - may have elevated transaminases before starting gluten free diet (GFD)

[Testing antigliadin antibodies are no longer recommended]

Rx

Conservative -

Gluten free diet - no barley, wheat, rye and sometimes no oats - bread, cakes, pies, cereals. Fresh meat, fish, fruit and vegetables form the core of the diet and the use of gluten-free substitute products.

Rice, maize, soya, potatoes, sugar, jam, syrup and treacle all allowed.

NHS prescribed gluten free biscuits, flour, bread and pasta.

Counselling and education - may benefit from Coeliac Society - regular meetings and activities.

Follow-up to check symptoms, take bloods, manage associated problems and detect and manage complications. Follow-up also with dietician.

Even minor dietary relapses can cause recurrence.

Prognosis and Complications

Complications:

> Malignancy - 80x risk small bowel Ca - Intestinal lymphoma (usually T cell), risk of extra-intestinal Ca too, especially oesophageal

> Ulcerative jejunitis

> Splenic atrophy

> Collagenous sprue - excessive subepithelial collagen deposition

> Osteoporosis

> Iron deficiency anaemia

> Neuropathies and myopathies

DIVERTICULAR DISEASE

Summary Points

• Diverticular disease is symptomatic diverticulosis, a disease where there are mucosal outpouchings of the gut wall

• Presentation varies by its possible complications, classically with left-sided abdominal pain

• It is diagnosed by sigmoidoscopy and CT

• Treatment is complication specific and may range from a conservative watchful waiting, to surgical resection

Aetiology and Pathophysiology

Firstly, it is important to understand the terminology that is often confused as being synonymous...

• Diverticula = a mucosal outpouching of the GI tract wall

• Diverticulosis = the presence of diverticulae

• Diverticulitis = inflammation of one or more diverticulae

• Diverticular disease = symptomatic Diverticulosis

It can be congenital but is largely an acquired disease

Diverticulae are classically found in the sigmoid colon but they can be anywhere and can become massive. They are typically 0.5-1cm in size.

Lack of fibre is thought to cause high intraluminal pressures -> force mucosa to herniate through gut wall at weaker points.

Epidemiology and Associated Risk Factors

~30% Westerners have diverticulosis by retirement age, so advancing age, and a poor diet, low in fibre, are the most significant risk factors. Other risk factors include obesity, smoking and the use of NSAIDs and paracetamol.

It is rare in those <40 yrs old, and rare in rural Africa and Asia. High prevalence in the USA, Europe and Australia.

Presentation

Presentation may be as an incidental finding. 70% are asymptomatic but possible symptoms include abdominal discomfort (left sided pain is classical) exacerbated by eating, constipation and rectal bleeding (occult or frank).

...or following one of its complications: (above picture plus- )

• Fistulae – most commonly colovesicular and colovaginal. Clinically present with urinary symptoms e.g. pneumaturia (gas/air in urine),...

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