Malbsorotion and small intestinal disease Flashcards
What are the functions of the small intestine?
Digestion
Absorption
Endocrine and neuronal control
Barrier against pathogens
What are the barrier functions of the small intestine?
Immune sampling
Monitoring of the presence of pathogens
Translocation of bacteria
Gut assocatied lymphoid tissue
What is the structure of the small intestine?
250-450cm
Villous architecture
Why is there a low bacterial population of the small intestine?
Digestive enzymes
Bile salts
Presence of IgA etc
Where does digestion commence?
Stomach
What are proteins broken down to?
Oligopeptides and amino acids
What happens to digested proteins at the brush border?
Final hydrolysis and absorption
What breaks down fats?
Pancreatic lipase
What are fats broken down to?
Glycerol and free fatty acids
How are glycerol and fatty acids absorbed?
Via lacteals into the lymphatic system
What are the causes of malabsorption?
Inflammation Infection Infiltration Impaired motility Iatrogenic Pancreatic
What are the inflammatory causes of malabsorption?
Coeliac
Crohn’s
What are the infective causes of malabsorption?
Tropica sprue HIV Giardia lambila Whipples diseae Tropheryma whippelii
What are the impaired motility causes of malabsorption?
Systemic sclerosis
Disabetes
Pseudo obstruction
What are the iatrogenic causes of malabsorption?
Gastric surgery
Short bowel syndrome
Radiation
What are the pancreatic causes of malabsorption?
Chronic pancreatitis
Cystic fibrosis
What are the symptoms of malabsorption?
Weight loss
Increased appetite
Steatorrhoea
What are the characteristics of steatorrhoea?
Stool floats, pale, foul smelling, may leave oily mark
What are the signs of malabsorption?
Specific deficiencies Clubbing Scleroderma Aphthous ulceration Dermatitis herpetiformis
What specific deficiencies can arise from malabsorption?
Iron
B12, folate
Ca, Mg, vit A, C, D, K
Vit B complex
What does Ca, Mg and vit D deficiency cause?
Tetany
Osteomalacia
What does a vit A deficiency cause?
Night blindness
What does a vit B complex deficiency cause?
Thiamine deficiency- memory, dementia
Niacin deficiency- dermatitis, unexplained heart failure
What i clubbing a sign of?
Crohn’s
coeliac
What is aphthous ulceration a sign of?
Crohn’s
Coeliac
What is the cutaneous manifestation of coeliac?
Dermatitis herpetiformis
IgA deposits in skin
What are the forms of small bowel investigation?
Tests of structure
Tests of function
Other
What are the structural tests of the small bowel?
Biopsy via endoscopy Barium swallow White cell scan CT MRI enterography Capsule enterography
What tests can be used to determine bacterial overgrowth?
H2 breath test
Culture of duodenal/jujenal aspirate
What is coeliac?
Sensitivity to the gladden fraction of gluten
What is gluten found in?
Wheat, rye, barley
What is gluten absent from?
Maize, rice, oats
What are the symptoms of coeliac?
Weight loss Diarrhoea and/or constipation Abdo pain Anaemia Fatigue Bloating Dermatitis herpeformis
What is the pathology of coeliac?
Produces inflammatory response, causing partial or total villous atrophy and increased epithelial lymphocytes
How is coeliac diagnosed?
Serology then if + distal duodenal biopsy
Whatvare the 3 levels of villous atrophy?
Partial- villi shortened
Subtotal- lining flat but glands extended
Total- lining flat
What is the treatment of coeliac?
Withdrawal of gluten
Referral o state registered dietician
What conditions are associated with coeliac?
Demartitis herpetiformis Type 1 diabetes Autoimmune thyroid disease Autoimmune hepatitis Primay biliary cirrhosis Autoimmune gastritis Sjogren syndrome IgA deficiency Downs Syndrome
What are the possible complications of coeliac?
Refractory coeliac disease Small bowel lymphoma Oesophageal carcinoma Colon cancer Small bowel adenocarcinoma
What is refractory coeliac disease?
Coeliac disease with doesn’t respond to diet
Treat with steroids
