Small Intestinal Disorders and Investigation Flashcards
What is the functions of the small intestine
Digestion
Absorption
Endocrine and neural control (flow of material from stomach to colon)
Barrier functions
How does the barriers function work against pathogens
Immune sampling
Monitoring the presence of pathogens
Translocation of Bacteria
Gut Associated Lymphoid Tissue (GALT)
What structures and features of the small intestine allow it to perform its function
Large surface area
- Villous architecture
- Constant turnover of cells in crypts & villi
Low Bacterial population
- toxic environment
Motility
How and Where does digestion begin
In the stomach by salivary amylase and pepsin
Why is there a controlled digestion in the stomach
To avoid osmotic shifts
What happens in the digestion of proteins
Breakdown to oligopeptides & amino acids
by Trypsin and chymotrypsin
Final hydrolysis and absorption at brush border
What happens in the digestion of fat
Pancreatic lipase breaks don fat into glycerol and free fatty acids
Absorption happens via lacteal and lymphatic system
What happens in the breakdown oc carbohydrates
Pancreatic amylase
Breakdown carbohydrate into disaccharides
Final digestion by brush border disaccharidase
What is the symptoms of small intestine disease
Weight Loss
Increased appetite
Diarrhoea
Steatorrhoea
Bloating
Fatigue
What is the cause of steatorrhoea
Fat malabsorption
causing high fat content on stool
What is the presentation of steatorrhoea
Stool less dense and floats
Pale
Foul smelling
May leave an oily mark or oil droplets
What is the signs of small intestine disease
Weight loss
Low or falling BMI
What deficiencies can occur due to small intestine disease
Iron Vitamin B 12 Vitamin A,C,D,K Vitamin B complex - Thiamine - Niacin Ca2+ Mg2+
What does a deficiency of iron and Vitamin b12 cause
Anemia
What deficiencies result in tetany osteomalacia (muscle spasms and softening of bones)
Ca2+
Mg2+
Vitamin D
What deficiency causes night blindness
Vitamin A
What deficiency result in a raised prothrombin time rate (PTR) - the time taken for blood to clot
Vitamin K
What is scurvy a deficiency of
Vitamin C
What does a thiamine deficiency result in
Memory,
Dementia
What does a Niacin deficiency result in
Dermatitis,
Unexplained heart failure
What is clubbing and aphthous ulceration (mouth ulcers) a non specific sign of
Coeliac disease
Crohns
What is scleroderma a non specific sign on
Systemic sclerosis
What is dermatitis herpetiformis a sign of
Is a sign of cutaneous manifestations of coeliac disease
What is the presentation of dermatitis herpetiforms
Blistering
Intensely itchy
Scalp, shoulders, elbows, knees
IgA deposit in the skin
What are examples of non specific signs of small intestine disease
Clubbing
Scleroderma
Aphthous Ulceration
Dermatitis herpetiformis
What are the investigations for the structure of the small intestine
Endoscopy + biopsy
Barium swallow
CT scan
MRI enterography
Capsule enterography
White cell scan
How do you specifically test for bacterial overgrowth in the small intestine
H2 Breath test
(H2 is a product of bacterial breakdown of lactulose/glucose so will be increased)
or
Culture a duodenal or jejunal aspirate
How do you test for coeliac disease
Serology -
IgA tests
(more reliable than IgG)
Distal duodenal biopsy
HLA status
Why should you check the total plasma IgA in diagnosing coeliac disease
Just in case patient has a selective IgA deficiency, so might not make IgA
What does distal duodenal biopsy investigate
See if there is villous atrophy
either partial/subtotal/total
Why do you investigate HLA (human leukocyte antigen) and why is it not that efficient
As 97% of coeliacs are either HLA DQ2 or DQ8
but so are 30% of the population
What causes Coeliac disease
A Sensitivity to Giladin
Component of gluten found in Wheat, Rye, Barley
What is the pathology of coeliac disease
Produces an inflammatory response
that results in Partial or subtotal villous atrophy
and Increased intra-epithelial lymphocytes
What is the enzyme attacked in coeliac disease
Tissue Transglutaminase
What is the investigations for Coeliac disease
Distal duodenal biopsy
Serology: +
- Anti endomysial IgA
- Anti Tissue transglutaminase
- Anti Gliadin (help in children but no diagnostic in adults
What is the treatment of coeliac disease
Withdraw gluten (avoid wheat, + lifelong diet)
MUST refer to state registered dietitian
What is associated conditions of Coeliac disease
Dermatitis herpetiformis
Insulin dependant diabetes mellitus
Autoimmune:
thyroid disease
hepatitis
Gastritis
Primary Biliary cirrhosis
Sjogren syndrome
IgA deficiency
Downs Syndrome
What is the complications of Coeliac disease
Refractory Coeliac Disease
Small bowel lymphoma
Oesophageal
carcinoma
Colon Cancer
Small bowel adenocarcinoma
What is the aetiology of malabsorption
Inflammation:
- Crohns
- Coeliac disease
Infection
- Tropical
- HIV
- Giardia lamblia (unicellular parasite found in contaminated water)
Whipples Disease
Amyloid (build up of starch/protein)
Impaired motility
- systemic scerlosis
- Diabetes
- Pseudo Obstruction
Iatrogenic
- Gastric surgery
- Short bowel syndrome
- Radiation
Pancreatic
- Chronic pancreatitis
- Cystic fibrosis
What is the treatment of giardia lamblia
Metronidazole
What does giardia lamblia result in
Hypogammaglobulinaemia
Giardiasis - Causing the symptom of diarrhoea
What is the presentation of whiles disease
Middle aged men
Skin, brain, joints and cardiac effects
Weight loss
Malabsorption
Abdominal pain
PAS material in villi
What is the causative organism of whipples disease
Tropheryma whippelii
When does small bowel overgrowth happen
When there is a condition that affect the motility, gut structure of the immunity of the small intestine
How do you treat small bowel overgrowth
Rotating antibiotics: Metronidazole Tetracycline Amoxycillin Each for 2 weeks
With Vitamin and nutritional supplements
Is it easier to test for the function or structure of the small intestine
Structure
