Disorders of the stomach Flashcards
Describe the lining of the stomach
- The stomach is lined with a specialised columnar epithelium, adapted with gastric pits that contain chief cells and parietal cells
- Chief cells are responsible for producing pepsin, and parietal cells secrete hydrochloric acid and release intrinsic factor
- Because of the stomach’s low pH environment, it is protected by surface cells that secrete mucus and bicarbonate
How does the stomach connect to the duodenum?
Via the pyloric sphincter
What does intrinsic factor do?
Intrinsic factor binds to vitamin B12, which essentially primes it to be abdorbed in the terminal ileum
What is dyspepsia?
Dyspepsia primarily refers to bloating and discomfort associated with the upper abdomen, it includes GORD symptoms.
How would you manage a patient presenting with dyspepsia?
- Most patients do not require investigations and can be treated conservatively:
- Medication review - steroids, NSAIDs, bisphosphonates, ect
- Lifestyle modification - alcohol cessation, dietry change
- Trial of antacids or alginates
- ALARM symptoms/ >55y
- Urgent endoscopy
- Unresponsive to conservative therapy
- Test for H. pylori (breath/stool)
- Positive - Eradication therapy
- Negative - Trial of PPI
- Test for H. pylori (breath/stool)
What is gastritis and what are the two subtypes?
Gastritis refers to inflamation of the stomach and is primarily a histological diagnosis.
This can be divided into acute and chronic gastritis, each of which is caused by very different pathologies.
Causes of acute and chronic gastritis
- Acute
- H. Pylori infection
- Alcohol
- NSAIDs, aspirin
- Stress-induced
- Bile acid reflux (usually post-gastric surgery)
- Chronic
- Chronic H. pylori infection
- Crohn’s disease
- Sarcoidosis
- Autoimmune (atrophic)
What is autoimmune gastritis?
Autoimmune gastritis is a chronic atrophic condition associated with the autoimmune destruction of parietal cells of the stomach. Severe gastric atrophy will result in insufficient intrinsic factor production, leading to pernicious anaemia.
Define peptic ulcer disease
Disease of the stomach or duodenal mucosa involving a break in the layer and loss of surface tissue.
Epidemiology of peptic ulcer disease
- Accounts for 13% of investigated dyspepsia
- Prevelence of less than 1% in the western population
Aetiology of peptic ulcer disease
- Helicobacter pylori infection
- Drugs - aspirin, NSAIDs
- Rare causes
- Zollinger-Ellison syndrome
- Crohn’s disease
- Secondary to
- Intracranial neurology (known as a Cushing ulcer)
- Burns or trauma (know as a Curling ulcer)
Clinical features of peptic ulcer disease
- Epigastric pain with post-prandial association
- Bloating, abdominal distension
- Nausea
Peptic ulcer - does the epigastric pain get better or worse after eating?
The epigastric pain related to duodenal ulcers classically improves upon eating, while the pain related to gastric ulcers is typically described as worse on eating.
Pathophysiology of peptic ulcer due to H. pylori
H. pylori, a Gram-negative, urase-producing bacterium (enabling it to survive in low pH conditions), lives in the stomach and duodeal mucosa.
The pathogen stimulates gastrin production as well as inhibiting somatostain production, resulting in an increase in acid secretion, which ultimately leads to gastric and duodenal ulceration.
Investigations for H. pylori
- Carbon-13 urea breath test (stop PPI medication 2 weeks before test as they may result in false positive tests)
- Stool antigen testing
- Laboratory-based serology testing