GI: Conditions of the small intestine Flashcards
What is the role of the small intestine?
To digest and absorb nutrients
What are the symptoms of small bowel disease?
Diarrhoea Steatorrhoea Abdominal pain/distension Anorexia Weight loss
What are the most common disorders of the small intestine that cause malabsorption?
Coeliac’s disease
Crohn’s disease
What investigations are indicated in a patient with small bowel disease symptoms and/or folate deficiency/vitamin B12 deficiency?
First line: Coeliac serology (tTG antibodies)
Small bowel barium follow through
Endoscopic small bowel biopsy
What is coeliac disease?
An autoimmune sensitivity to gluten
Associated with HLA DQ2 in 95% of people
What is the toxic portion of the gluten molecule?
Alpha-gliadin
What histological findings are characteristic of coeliac disease?
Abnormal jejunal mucosa
Villous atrophy
Crypt hyperplasia
What two age groups does coeliac disease present in?
Infancy
Adults in their 50s
What signs + symptoms might a patient with coeliac disease present with?
Small bowel disease symptoms (typically diarrhoea and weight loss)
or
Symptoms may be non specific (malaise/fatigue)
Physical signs related to anaemia/malnutrition: angular cheillitis + apthous ulcers
Which patients should be offered coeliac serology testing?
Patients with: A first degree relative affected by the disease Type 1 diabetes Thyroid disease Autoimmune liver disease Down's syndrome IBS
What is the first-line investigation for coeliac disease?
Serology: anti-tTG antibodies
How is coeliac disease diagnosed?
Duodenal biopsy
What other investigation is performed at the diagnosis of coeliac disease?
Bone densitometry due to increased risk of osteoporosis
Which vaccine is given in coeliac disease?
Pneumococcal vaccine due to association of hyposplenism (reduced spleen function)
What is dermatitis herpetiformis?
An itchy, symmetrical rash that indicates underlying coeliac disease
How is dermatitis herpetifromis diagnosed?
Skin biopsy + serology for ETG antibodies
How is dermatitis herpetiformis treated?
Dapsone (antibiotic) + gluten free diet
What is whipple’s disease?
A rare, bacterial infection of the small bowel
What are the symptoms of whipple’s disease?
Steatorrhoea Abdominal pain fever arthritis Lymphadenopathy
What sign is seen on biopsy for Whipple’s disease?
Acid Schiff positive macrophages
How is whipple’s disease treated?
Co-trimoxazole for 1 year
Reactivation of primary TB can affect which part of the GI tract?
Ileocaecal valve
What are the common causes of mesenteric ishaemia?
Atherosclerosis
Thromboembolism
What is the main symptom of mesenteric ishaemia?
Cramping abdominal pain
How is mesenteric ishaemia diagnosed?
Angiography
How is mesenteric ishaemia treated?
Urgent surgery
How do tumours of the small intestine present?
Abdominal pain
Diarrhoea
anorexia
weight loss
Are primary or secondary tumours of the small bowel more common?
Secondary- primary tumours are rare
What is the most common malignant tumour of the small bowel?
Adenocarcinoma
What cells does a lymphoma arise from?
T and B cells
Increased incidence in coeliac and crohn’s patients
What cells does a carcinoid tumour arise from?
Enterocromaffin cells
What is gallstone ileus?
When a large gallstone migrates via fistulas into the small intestine and becomes lodged
What is the name of the most common fistula between the gall bladder and small intestine?
Cholecystoduodenal fistula
What are the symptoms of small bowel obstruction?
Colicky abdominal pain Absolute constipation (no passing of gas) Abdominal distension Faeculent vomiting
What is the buzz word for small bowel obstruction?
Tinkling bowel sounds
What can cause small bowel obstruction?
Adhesions from previous surgery
Crohn’s disease (narrowing due to inflammation + scarring)
Tumours
Hernias
What investigations are done in suspected bowel obstruction?
AXR
Contrast Abdo CT
FBC
Urine analysis
How is small bowel obstruction managed?
‘Drip and Suck’ - NG tube drain + IV fluids and potassium
Is surgery indicated in small bowel obstruction?
Most cases settle without surgical intervention
ONLY indicated if there is risk of strangulation, perforation or ischaemia
Which histological part of the bowel is most sensitive to hypoxia?
The mucosa as it is most metabolically active
