Maldigestion and Malabsorption Flashcards
1
Q
What is maldigestion?
A
Inability to break down large molecules in the lumen of the intestine into their component small molecules.
2
Q
What is malabsorption?
A
Inability to transport molecules across the intestinal mucosa into circulation.
3
Q
What is malassimilation?
A
Encompasses both maldigestion and malabsorption.
4
Q
What is the aetiology of maldigestion?
A
- Inadequate mixing of food w/ enzymes (e.g. post-gastrectomy)
- Pancreatic exocrine deficiency / Primary disease of the pancreas (CF, Ca, pancreatitis)
- Bile salt deficiency
- Bacterial overgrowth
- Specific enzyme deficiencies (e.g. lactase)
5
Q
What are the causes of bile salt deficiency?
A
- Cholestatic liver disease
- Terminal ileal disease (impaired recycling)
- Bacterial overgrowth (deconjugation of bile salts)
6
Q
What are the causes of malabsorption?
A
- Inadequate absorptive surface
- Drug induced (cholestyramine, ethanol, neomycin, tetracycline and other ABx)
- Endocrine (diabetes)
7
Q
What causes inadequate absorptive surface?
A
- Infections: e.g. Whipple’s disease, Giardia
- Immunologic or allergic injury e.g. Coeliac disease
- Infiltration e.g. lymphoma, amyloidosis
- Fibrosis e.g. scleroderma, radiation enteritis
- Bowel resection
- Extensive Crohn’s disease
8
Q
Ix in malabsorption / maldigestion?
A
- Transglutaminase serology
- CTA
- FBE
- Coags
- Iron studies
- CMP
- LFTs
- 72h stool collection
9
Q
CFx malabsorption/digestion?
A
- Weight loss
- Diarrhoea
- Steatorrhoea
- Weakness
- Fatigue
- Manifestations of deficiency
10
Q
Ddx blood, mucousy diarrhoea w/ tenesmus?
A
Usually inflammatory mechanism:
1) Infection (Salmonella, Shigella, Yersinia, E. Histolytica)
2) IBD
3) Ischaemic colitis
4) Radiation colitis
