What mechanisms prevent gastric reflux?
Lower oesophageal sphincter (LES):
Usually closed, transiently relaxes to allow bolus through
Angle of His and mucosal flap valve, as well as the postero-lateral location of the fundus all prevent acid reaching the LES and refluxing
Right crus of diaphram acts as a sling around the oesophagus serving as an 'extrinsic' sphincter
The failure of anti-reflux mechanisms leads to what?
Prolonged contact of gastric juices with oesophageal mucosa
Gastro-oesophageal reflux disease and associated symptoms
What are the typical clinical features of Gastro-oesophageal reflux disease (GORD)?
Worsens on lying down, bending over or drinking hot drinks
What investigations are indicated by a history that leads you to suspect GORD?
No investigations done in typical clinical presentations
Only if worrying symptoms, such as dysphagia or hiatus hernia are suspected
Endoscopic investigation in this case
What are some of the risk factors for GORD?
Pregnancy or obesity
Fat, Chocolate, Coffee or Alcohol
List lifestyle management techniques to prevent/treat GORD
Reduce consumption of chocolate, coffee, alcohol, fatty foods
Outline the types of treatment available for GORD, including their mechanism and an examples of each type
Neutralises acid with a base
E.g. Calcium carbonate
Raft antacids (alginates):
Forms a protective raft that sits on top of stomach contents and prevents reflux
Reduction of acid secretion by oxyntic cells
Blocks H2 receptor which reduces acid secretions
What is a common complication of GORD?
Continual contact of gastric juices and oesophageal mucosa can lead to metaplastic change (Barrett's Oesophagus)
What is Gastritis?
Chronic or acute inflammation of the gastric mucosa
Differentiate acute and chronic gastritis
Infection with H. pylori
Inflammatory changes to mucosa leadsing to atrophy and metaplasia (possible cancer)
NSAIDs, Alcohol, Cocaine
Exfoliation of surface cells and decreased secretion of protective mucus
What are the common symptoms of gastritis?
Symptoms when they appear include:
- Dyspepia (Pain/Discomfort)
Outline the complications of Gastritis
Increases risk of Peptic ulcer disease
Chronic gastritis can cause hypergastrinaemia due to increasing gastrin release from G cells, this in turn can lead to Duodenal ulceration (DU)
Chronic Antral H. Pylori gastritis can lead to Gastric cancer and mucosa associated lymphoid tissue lymphoma (MALT Lymphoma)
How is gastritis diagnosed?
Testing for H. Pylori
Blood test (Anaemia due to GI bleed)
Stool test (Blood due to GI bleed)
What types of drugs are used to treat gastritis?
General theme is reduction in acid secretion for promotion of healing
Treatment of H. Pylori infection
What is peptic ulcer disease?
A break in the superficial epithelial cells down to the muscularis mucosa of either stomach (GU) or duodenum (DU)
Where are peptic ulcers commonly found?
Lesser curvature and antrum
Outline the most common cause of peptic ulcer disease
Inhibit prostaglandins and reduce production of unstirred layer of mucus
50% of patients with long term NSAIDs have mucosal damage
30% when endoscoped have petic ulcer(s)
5% are symptomatic
1-2% have complications such as GI bleed
What is the prevlance of the different forms of peptic ulcer disease and how do prevalence rates vary across ages and countries?
DU in 10% adult population
GU is 2-3x less common (3-5%)
Prevalence is lower among younger adults and higher in older
Developing countries have increasing prevalence of NSAID associated DU and decreasing prevalence of H. Pylori associated ulceration
What are the clinical features of Peptic ulcer disease?
Reccurent, burning epigastric pain:
Worse at night and when hungry in DU
Relieved by eating
Persistent severe pain:
Suggestive of penetrtion of ulcer into other organs
Suggests penetration of ulcer in posterior stomach
Nausea and vomitting:
Weight loss and anorexia:
Asymptomatic patients can suddenly present with haematemesis when a blood vessel is erroded
What are the common investigations for suspected Peptic ulcer disease?
Investigation of H. Pylori infection
In 55+ patients or those with alarming symptoms an endoscopy can be done to exclude cancer
How is peptic ulcer disease managed?
Antibiotics for H. Pylori (Clarithromycin/Amoxicillin)
If taking NSAIDs, review use and perhaps use alternatives
NSAIDs and PPIs used together if NSAIDs are long term
What are the complications of peptic ulcer disease?
Haemorrhage of blood vessels:
More common in DUs, normally into peritoneal cavity
Gastric outlet obstruction:
Can be pre-pyloric, pyloric or duodenal
Occurs due to active ulcers w/oedema or due to healing of ulcer with associated fibrosis/scarring
Normally presents as vomiting without pain
Describe H. pylori bacteria
Gram negatic, Aerobic
Found in the mucus layer of the stomach or adhered to gastric mucosa
What is the significance of H. pylori producing urease?
Urease produces ammonia and CO2
Used to neutralise surroundings and protect the bacterium
C13 Urea test:
C13 Urea can be ingested by the patient to test for H. Pylori infection
Urease breaks down C13 urea forming C13 CO2 which can be exhaled and detected
How does H. Pylori colonisation of the gastric mucosa cause disease?
Secretion of enzymes and other substances that damage mucosa:
Ammonia is toxic to epithelia
Vacuolating cytotoxin A disrupts tight junctions and leads to apoptosis
Inflammatory response to bacterium (Inflammatory cells and mediators)
What are some of the diseases caused by H. pylori infection?
Peptic ulcer disease
How does H. pylori colonisation in different areas of the stomach affect clinical outcomes?
Antrum predominant colonisation:
Antrum and body colonisation:
GU and cancer risk
How is a bacterium implicated only in the colonisation of the stomach cause DU?
Antral H. pylori infection leads to hypergastrinaemia and hence increased acid production from oxyntic cells
Duodenal cap is inflammed and damaged by excess acid and metaplasia can occur
H. pylori colonises inflammed duodenal cap
Duodenal immune response leads to duodenitis and development of ulceration which is common intermittent
How can we test for H. pylori infection?
C13 Urea test
IgG serum levels
Gastric biopsy taken and H. pylori detected by histology and culture
How is H. pylori infection treated?
Same as Gastritis, GU or DU with H. pylori being the cause
PPI, H2 antagonist, Antibiotics (Clarithromycin/Amoxicillin)
90% successful in treatment of H. pylori