GI8 - Pathophysiology of Gastric Disease

Question 1

5 features of gastro-oesophageal reflux disorder (GORD)

Definition
Risk Factors x6
Symptoms x3
Consequences x5
Treatment

Answer 1

1.) Definition - stomach acid leaks up the oesophagus

2. ) Risk Factors - obesity, ↑age, smoking, alcohol
   - ↑intra-abdominal pressure e.g. pregnancy, obesity,
   - hiatal hernias (LOS moves into thorax)
   - delayed gastric emptying
3. ) Symptoms - chest pain, cough, acidic taste
   - described as heartburn, reflux, or indigestion
4. ) Consequences - asymptomatic or symptomatic:
   - oesophagitis, strictures, ulceration, haemorrhage
   - Barrett’s oesophagus (metaplasia of stratified squamous –> columnar) in distal oesophagus
5. ) Treatment - lifestyle (smaller meals, not eating just before sleeping, losing weight)
   - drugs (antacids, PPIs, H2 antagonists),
   - surgery (fundoplication), can cause dysphagia

Question 2

4 features of acute gastritis

Definition/Cause
Risk Factors x4
Symptoms x3
Treatment

Answer 2

1. ) Definition - sudden inflammation of stomach lining
   - chemical injury causes damaged epithelial mucosal cells and reduction in mucous production
   - mucosa responds via acute inflammation
2. ) Risk Factors
   - heavy use of NSAIDs ↓ prostaglandin synthesis
   - alcohol dissolves mucous layers
   - chemotherapy damages rapidly dividing gut cells
   - bile reflux as bile is an irritant to the stomach
3. ) Symptoms - asymptomatic or symptomatic
   - abdominal (epigastric) pain, N/V, bleeding (fatal)

4.) Treatment - removal of the irritant

Question 3

4 features of bacterial chronic gastritis

Mechanism
Symptoms
Consequences
Diagnosis and Treatment

Answer 3

1. ) Mechanism - H.pylori
   - releases cytotoxins causing direct epithelial injury
   - degrades mucus layer
   - promotes inflammatory response –> self injury

2.) Symptoms - similar to acute gastritis

3. ) Consequences - depends on colonisation location
   - peptic ulcers, adenocarcinoma, MALT lymphoma
4. ) Diagnosis and Treatment
   - urea breath test and stool antigen test
   - treat using PPIs and amoxicillin + (clarithromycin or metronidazole)

Question 4

4 features of autoimmune chronic gastritis

Mechanism
Risk Factors
4 Symptoms
Consequences

Answer 4

1. ) Mechanism - antibodies attack gastric parietal cells
2. ) Risk Factors - chemical/reactive, alcohol, NSAIDs, bile reflux
3. ) Symptoms - mainly symptoms of anaemia
   - glossitis (tongue inflammation)
   - anorexia because eating is uncomfortable
   - neurological symptoms due to B12 deficiency
4. ) Consequences - anaemia
   - iron deficiency anaemia due to lack of acid needed for iron absorption
   - pernicious anaemia due to lack of IF needed for B12 absorption

Question 5

5 features of Helicobacter pylori (H.pylori)

Gram Staining
Structural Features
Spread
Protective Mechanisms x2

Answer 5

1. ) Gram Staining - gram negative
2. ) Structural Features - helix shaped, adhesins, flagellum
3. ) Spread - oral to oral/faecal to oral
4. ) Urease - converts urea to ammonium
   - increases local pH, allowing for survival in acidity
5. ) Adhesins - allows adhesion to gastric mucosa
   - helps to resist peristalsis

Question 6

3 effects of colonisation location of H.pylori and the consequences

Answer 6

1.) Body and Antrum - asymptomatic

2. ) Antrum - can lead to duodenal ulcers
   - increased gastrin secretion –> increased acid secretion –> duodenal epithelial metaplasia –> duodenum colonisation –> duodenal ulceration
3. ) Body - can lead to gastric ulcers or cancer
   - atrophic effect –> gastric ulcer
   - atrophic effect –> intestinal metaplasia –> dysplasia
   - -> cancer

Question 7

6 features of peptic ulcer disease

Definition
Common Location
Mechanism
Causes
Symptoms
Diagnosis and Management

Answer 7

1. ) Definition - painful ulcers in the lining of the stomach
   - caused by defects in gastric/duodenal mucosa
   - extends through muscularis mucosa
2. ) Common Locations - first part of the duodenum
   - also common on the lesser curve/antrum of stomach
   - acute develops as part of acute gastritis
   - chronic occur most frequently at mucosal junctions e.g. where antrum meets body on lesser curve and where duodenum meets the jejunum
3. ) Mechanism - due to breakdown of normal defences rather than excessive acid production
   - often due to rapid gastric emptying or inadequate acid neutralisation from bile
4. ) Causes - mucosal injury
   - H.pylori, NSAIDs, smoking (relapse), stress e.g. burns
   - pepsin, alcohol, bile acids, steroid, stress
5. ) Symptoms - post-prandial epigastric burning pain
   - can sometimes also have back pain
   - if duodenal can have pain w/out food in stomach
   - more serious symptoms are: haematemesis (vomiting blood), early satiety from repeated scarring, weight loss
6. ) Diagnosis and Management
   - testing for H.pylori and endoscopy
   - treat using lifestyle modifications, stop exacerbating medications, and PPIs, antacids

Question 8

3 morphological features of peptic ulcer disease

Size
Base
Scar Tissue

Answer 8

1. ) Size - < 2cm in diameter but can get to 10 cm
2. ) Base - necrotic/granulation tissue
3. ) Scar Tissue - muscularis propria can be replaced by scar tissue

Question 9

5 clinical consequences of peptic ulcer disease

Answer 9

1. ) Pyloric Stenosis - scar tissue shrinks and narrows stomach lumen or pyloric sphincter
2. ) Peritonitis - ulcer perforates peritoneum
3. ) Erosion - into adjacent structures (liver or pancreas)
4. ) Haemorrhage - from vessel in base of ulcer
5. ) Malignancy - rare

Question 10

What is functional dyspepsia

Answer 10

When you have symptoms of ulcer disease but no physical evidence of organic disease

This is diagnosed by exclusion

Question 11

3 features of Zollinger-Ellison syndrome

Mechanism
Consequences
Symptoms

Answer 11

1. ) Mechanism - pancreatic tumour secretes gastrin
   - proliferation of parietal cells –> lots of acid production
2. ) Consequences - severe ulceration of the stomach and small bowel
3. ) Symptoms - abdominal pain and diarrhoea

Question 12

3 features of stomach cancer

Prevalence
Risk Factors
Symptoms

Answer 12

1. ) Prevalence - 3rd most common cancer in the world
2. ) Risk Factors - male, H.pylori, diet, smoking
3. ) Symptoms - presents late since it has to be quite large before you get symptoms:
   - dysphagia, loss of appetite, blood in stool, weight loss, nausea/vomiting, enlarged Virchow’s nodes