Malabsorbtion and Small Intestinal Disease Flashcards
what are four general functions of the small intestine?
> digestion
absorption
endocrine/neural functions
barrier to outside
how does the small intestine act as a barrier?
> immune sampling, bacteria pulled through the wall intact then smashed up by white blood cells that review their antigens
monitoring pathogen presence
translocation of bacteria
gut associated lymphoid tissue
why is breakdown controlled in the stomach?
to avoid osmotic shifts
where does protein digestion begin?
the small intestine
what system are glycerol and free fatty acids transported through within the body?
the lacteal and lymphatic system
what symptoms are seen with small intestinal disorders?
> weight loss > increased appetite > diarrhoea > bloating > fatigue (v. vague) > Steatorrhoea
how may patients describe steatorrhea (not the clinical definition but what patients may actually describe)?
> foul smell
> orange oil that floats
what signs are associated with small intestinal disorders?
falling/low BMI
what signs may specifically accompany calcium, magnesium and vitamin d deficiency?
> tetany (spasming/twitching of muscles)
> osteomalacia
what may vit. a deficiency cause?
night blindness
what are the signs of vit. k deficiency?
raised PT (prothrombin time)
what are signs of vit b complex deficiencies?
> thiamine: dementia
> niacin: dermatitis, unexplained heart failure
what are signs of vit. c deficiency?
scurvy
what conditions may cause clubbing?
coeliac or crohns
what may be causing sclerodoma?
systemic sclerosis
what is aphthous ulceration a general sign of?
coeliac and crohns
describe dermatitis herpetiforms
> cutaneous manifestation of coeliac disease > blistering > intense itching > scalp, shoulders, elbows, knees > IgA deposit in skin
name some tests of the structure of the small bowel
> small bowel biopsy (endoscopy) > small bowel study (barium swallow) > white cell scan > CT scan > MRI enterography >capsule enterography
how may you measure bacterial overgrowth?
> h2 breath test (lactulose/glucose substrate)
> culture of duodenal jejunal aspirate
in a distal duodenal biopsy what three levels of villus atrophy are there?
> partial
subtotal
total
what are coeliacs sensitive to in wheat, rye and barley?
gliadin fraction of gluten
from what is gliadin absent?
rice and maize and oats (oats are mostly contaminated with wheat anyway due to farming methods)
describe the pathology of coeliac’s disease
> inflammatory response (tissue transglutaminase)
partial/subtotal villus atrophy
increased intra-epithelial lymphocytes
what test would you use to diagnose coeliac’s?
distal duodenal biopsy
what serology is used to diagnose coeliac’s?
> anti endomysial IGA
anti tissue transglutaminase
anti-gliadin is useful in children but not adults
what is the treatment for coeliac disease?
> withdraw gluten
refer to state registered dietitian
coeliac support group
what conditions are associated with coeliacs?
> Dermatitis herpetiformis > IDDM > Autoimmune thyroid disease > Autoimmune hepatitis > Primary Biliary cirrhosis > Autoimmune gastritis > Sjogren syndrome > IgA deficiency > Downs Syndrome
what complications are associated with coeliacs?
> refractory coeliac disease > small bowel lymphoma > oesophageal carcinoma > colon cancer > small bowel adenocarcinoma
what inflammatory problems lead to malabsorption?
> coeliac disease
> crohns
what infections lead to malabsorption?
> tropical sprue
HIV
giardia lamblia
describe giardia lamblia
> unicellular parasite found in contaminated water
> responds to metronidazole
what causes malabsorption?
> whipples disease ( causative organism is tropheryma whippelii) > infiltration > impaired motility > iatrogenic > pancreatic disease > inflammation > infection
describe the effects of whipples disease
> skin, brain, joints and cardiac effects
weight loss
abdominal pain
PAS material in the villi
What pancreatic conditions can lead to malabsorption?
> Cystic fibrosis
> Chronic pancreatitis
What infiltration conditions can lead to malabsorption?
Amyloidosis
What conditions which cause impaired motility can result in malabsorption?
> Systemic sclerosis
Diabetes
Pseudo obstruction
What are some iatrogenic causes of malabsorption?
> Gastric surgery
Short bowel syndrome
Radiation
