Malabsorption (GI) Flashcards
Define malabsorption.
Malfunction of the intestinal wall resulting in insufficient absorption of breakdown products
What diseases can cause malabsorption? (3)
- IBD (Crohn’s, UC)
- Coeliac disease
- lactose intolerance
Define global malabsorption.
In diseases causing diffuse mucosal damage or reduction in absorptive surface e.g. Coeliac
Define partial malabsorption.
Localised absorption impairment resulting in deficiencies of specific nutrients e.g. vitamin B12 deficiency in patients with disease of terminal ileum
Define maldigestion.
Insufficient secretion of pancreatic enzyme or bile preventing adequate breakdown of food in intestinal lumen
What can cause maldigestion? (2)
Exocrine pancreatic insufficiency OR cholestasis
What are the clinical features of malabsorption? (5)
- diarrhoea
- steatorrhoea - floating and foul-smelling stool
- abdominal distension
- weight loss and fatigue
- partial malabsorption - Sx specific to individual nutrient deficiencies
What do we see on bloods in malabsorption?
Anaemia and vitamin deficiencies
How do we assess absorptive function of upper small intestine (malabsorption)?
D-xylose absorption test
How do we manage malabsorption (non-severe)?
- oral supplementation of fluid, nutrients and vitamins
- calorie and protein-enriched diet
How do we manage severe malabsorption?
IV nutrition
What is a gastric cause of malabsorption?
Post-gastrectomy (Dumping syndrome)
What are some small bowel causes of malabsorption? (3)
- Coeliac disease
- Crohn’s disease
- small bowel resection (fatty stool, diarrhoea)
What are some pancreatic causes of malabsorption - loss of digestive enzymes –> maldigestion? (3)
- chronic pancreatitis (ADEK deficiency)
- pancreatic cancer
- cystic fibrosis
What are some hepatobiliary pathway causes of malabsorption? (2)
- primary biliary cirrhosis (PBC)
- ileal resection (failure of bile acid absorption at terminal ileum) –> fatty stool, diarrhoea
What are the features of vitamin A deficiency (malabsorption)?
Loss of vision –> blindness
What are the features of vitamin B1 deficiency (malabsorption)?
Thiamine
- muscle weakness
- severe weight loss (Beri-Beri)
- chronic alcohol use
- replace via IV Pabrinex
What are the features of vitamin B2 deficiency (malabsorption)?
Riboflavin - poor diet and mouth sores (ariboflavinosis)
What are the features of vitamin B3 deficiency (malabsorption)?
Niacin - diarrhoea and dermatitis (pellagra)
What are the features of vitamin B5 deficiency (malabsorption)?
Pantothenic acid - ischaemic attacks, MS affect brain, paraesthesia
What are the features of vitamin B6 deficiency (malabsorption)?
Pyridoxine - low RBCs
What are the features of vitamin B7 deficiency (malabsorption)?
Biotin - red and itchy skin (dermatitis)
What are the features of vitamin B9 deficiency (malabsorption)?
Folic acid - immature RBCs in bone marrow –> megaloblastic anaemia
What are the features of vitamin B12 deficiency (malabsorption)?
Cyanocobalamin - abnormal absorption in small intestine, pernicious anaemia
What are the features of vitamin C deficiency (malabsorption)?
Ascorbic acid - bleeding gums and swollen joints, scurvy
What are the features of vitamin D deficiency (malabsorption)?
Calciferol - weakening of bones near joints, rickets
What are the features of vitamin E deficiency (malabsorption)?
Tocopherols - faster depletion of RBCs from body, haemolytic anaemia
What are the features of vitamin K deficiency (malabsorption)?
Phylloquinone - irregular and slow bleeding and clotting, bleeding diathesis
Required for synthesis of clotting factors II, VII, IX, X therefore deficiency due to malabsorption may result in bleeding diathesis
What are the fat-soluble vitamins and when is their absorption impaired?
Vitamins A, D, E, K
Absorption impaired in fat malabsorption syndromes e.g. biliary obstruction, Coeliac disease, CF, short-gut syndrome & chronic pancreatitis
