Digestive Flashcards
What are two key histological findings in Crohn disease?
- Transmural inflammation (mucosa to serosa)
- Non-necrotising granuloma
Why might patients with Crohn disease present with anaemia and/or iron and B12 deficiency?
- Anaemia due to bleeding from chronic inflammation
- Iron/B12 deficiency if small intestine is affected, less efficient absorption
Which part of the GI tract is affected by Crohn disease?
Entire tract can be affected, most commonly ileum + colon
What is the most commonly used anti-inflammatory for Crohn disease?
5-ASA
Which investigations are most commonly used for structural conditions of the oesophagus?
Gastroscopy and barium swallow
Which investigations are most commonly used for functional conditions of the oesophagus?
Manometry and pH study
How would a baby with an oesophageal fistula present?
Frequent vomiting following feeding
A patient presents with:
- Heartburn
- Regurgitation
- Bitter taste in the mouth
- Exacerbation when lying down
What GI pathology could this relate to?
GORD
What is Barrett’s Oesophagus?
Transition from stratified squamous to columnar, glandular epithelium in the oesophagus following chronic acid exposure
What are key symptoms of reflux oesophagitis?
- Pain/discomfort in chest
- Bleeding (haematmesis)
- Dysphagia
Chronic GORD can lead to which conditions?
- Reflux oesophagitis
- Peptic stricutration
- Oesophageal cancer (AdenoCa)
Anatomically, where are you most likely to find oesophageal SqCC?
High in the oesophagus
Which form of oesophageal cancer is associated with smoking, alcohol and poor diet?
SqCC
What is Zenker’s diverticulum?
A pouch that develops at the weakest portion of the pharynx due to excessive pressure
What are viral causes of oesophageal ulceration?
Herpes simplex, cytomegalovirus
What are pill induced causes of oesophageal ulceration?
Dioxycycilne and bisphosphonates
What is a characteristic macroscopic feature of eosinophilic oesophagitis?
Rings/circles/fissures in the oesophagus
What is achalasia?
Degeneration of the myenteric plexus and LOS inhibitory nerve
What causes the ‘bird beak’ appearance of an x-ray of a patient with achalasia?
- Loss of peristalsis in distal oesophagus
- Failure of LOS to relax with swallow
How does scleoderma affect the oesophagus?
- Absent peristalsis
- LOS has no tone
- Weak contraction
Why would manometry show high amplitude of contraction for nutracker oesophagus?
Normal peristalsis but amplitude of contraction is too strong
Why is vomiting of patients with congenital hypertrophic pyloric stenosis non-billous?
Stomach contents do not enter the duodenum due to thickening of pyloric wall
Which gastric tumour produces excess gastrin, causing destruction of gastric mucosa?
Gastrinoma
Which cell type is destroyed in pernicious anaemia?
Parietal cells
What are the symptoms of peptic ulcer disease?
- Burning epigastric pain
- Bleeding
- Perforation
- Obstruction
Which antibiotics comprise ‘triple therapy’ for peptic ulcer disease?
- Omeprazole
- Clarithromycin
- Amoxycillin
Which gastric cells secrete HCl?
Parietal cells
Why are cramping and diarrhoea symptoms of rapid gastric emptying?
Due to osmotic effect of large particles and fluid in the small intestine
What is the mechanism of H2 antagonists?
- Bind to H2 receptors on parietal cells for histamine
- Prevents parietal cell stimulation
What is the most commonly used H2 receptor antagonist?
Ranitidine
Why are H2 antagonists not effective for heartburn/oesophagitis?
Don’t allow mucosal healing - acid still secreted
What is the mechanism of action of PPIs?
Irreversibly bind to an activated proton pump
What are consequences of prolonged acid inhibition (e.g. chronic use of PPIs)?
- Bacterial overgrowth
- Lack of sterilisation
- Impaired absorption
- ECL hyperplasia