Malabsorption

Question 1

what is malabsorption

Answer 1

defective mucosal absorption

Question 2

what leads to malabsorption

Answer 2

defective luminal digestion,
mucosal disease,
structural disorders

Question 3

what are the common causes of malabsorption

Answer 3

coeliac disease, crohns disease, post infectious, biliary obstruction, cirrhosis

Question 4

what are the uncommon causes of malabsorption

Answer 4

pancreatic cancer, parasites, bacteria overgrowth, drugs, short bowel

Question 5

what are the two types of protein malabsorption

Answer 5

digestive and absorptive

Question 6

what are the digestive causes of protein malabsorption

Answer 6

partial/total gastrectomy (poor mixing),

exocrine pancreatic insufficiency

trypsinogen deficiency

congenital deficiency of intestinal enterokinase

Question 7

what are the absorptive cause of protein malabsorption

Answer 7

celiac disease and tropical sprue

methionine malabsorptive syndrome & blue diaper syndrome

SBS

jejunoileal bypass

defects in neutral amino acid transporters

cystinuria I-III

occulocerebral syndrome of lowe

Question 8

where does the digestive process of fat digestion occur

Answer 8

pancreas and liver

Question 9

where does the absorptive process of fat digestion occur

Answer 9

jejunal mucosa

Question 10

where does the post absorptive process (delivery) of fat digestion occur

Answer 10

in the lymphatics

Question 11

what can cause digestive fat malabsorption

Answer 11

(less time mixing)
gastric resection, autonomic neuropathy, amyloidosis

decreased bile secretion- cirrhosis, biliary obstruction, CCK deficiency

(decreased lipolysis)
CF, chronic pancreatitis, tumours, low pH

Question 12

what can cause absorptive fat malabsorption

Answer 12

descreased chlyomicron formation/ absorption, coeliac disease, chylomicron retention disease

Question 13

what can cause post absorptive fat malabsorbtion

Answer 13

defective lymphatic transport- lymphoma, trauma, retroperitoneal fibrosis

Question 14

what can cause digestive carb malabsorbtion

Answer 14

severe pancreatic insufficiency (alpha- amylase deficiency)

Question 15

what can cause absorptive carb malabsorption

Answer 15

primary or acquired lactase deficiency

• post infectious lactase deficiency
• celiac disease
• crohns
• sucrase-isomaltase deficiency
• trehalase deficiency

Question 16

what vitamins are commonly malabsorbed

Answer 16

B12, folic acid, fat soluble vitamins (ADEK) - anything that disrupts fat absorption

Question 17

what minerals are common malabsorbed

Answer 17

calcium, magnesium, iron (most common), zinc, copper

Question 18

describe coeliac disease and the pathology behind it

Answer 18

exposure to wheat, barley or rye induces a characteristic mucosal lesion

intestinal antigen-presenting cells in people expressing HLA-DQ2, or HLA-DG8, bind with dietary gluten peptides in their antigen-binding grooves activate specific mucosal T lymphocytes, producing cytokine mucosal damage

Question 19

what are the symptoms of coeliac disease

Answer 19

weight loss, diarrhoea, excess flatus and abdominal discomfort

Question 20

how is coeliac disease diagnosed

Answer 20

IgA anti tissue transglutaminase test (tTGA), biopsy confirmative

Question 21

what causes lactose malabsorption

Answer 21

deficiency of lactase

Question 22

what are the clinical features of lactose malabsorption

Answer 22

history of the induction of diarrhoea, abdominal discomfort, flatulence following the ingestion of dairy products

Question 23

how is lactose malabsorption diagnosed

Answer 23

lactose breath hydrogen test, oral lactose intolerance test

Question 24

how is lactose intolerance treated

Answer 24

lactose free diet

Question 25

what is tropical sprue

Answer 25

colonisation of the intestine by an infectious agent or alterations in the intestinal bacterial flora induced by the exposure to another environmental agent

Question 26

what are the clinical features of tropical sprue

Answer 26

diarrhoea, steatorrhea, weight loss, nausea, anorexia, anaemia, biopsy

Question 27

how is tropical sprue treated

Answer 27

tetracycline + folic acid

Question 28

what is whipples disease

Answer 28

commonly in white males, absorption in intestine reduced. caused by tropheryma whipplei, multi system involvement

Question 29

what are the clinical features of whipples disease

Answer 29

weight loss, diarrhoea, steatorrhea, abdominal distention, arthritis, fever, nutritional deficiency syndromes

Question 30

how is whipples disease diagnosed

Answer 30

demonstration of T. whipplei in involved tissues by microscopy

Question 31

how is whipples disease treated

Answer 31

antimicroial

Question 32

crohns disease patients with what other co-morbidities can develop severe malabsorption

Answer 32

extensive ileal involvement, extensive intestinal resections, enterocolic fistulas, strictures leading to small intestine bacterial overgrowth

Question 33

what are the clinical features of crohns disease

Answer 33

abdominal pain and diarrhoea, fever, weight loss, abdominal tenderness - most classically in the right lower quandrant

Question 34

how is crohns disease diagnosed

Answer 34

endoscopy, barium imaging of small bowel mucosal disease, CT, MRI, colonoscopy

Question 35

how is crohns disease treated

Answer 35

steroids, immunosuppresants, azathioprine 6-MP, biological therapy (anti TNF)

Question 36

what are the risk factors for the parasitic infection giardia Iamblia

Answer 36

travel to areas where the water supply may be contaminated/ swimming in ponds

Question 37

what are the clinical features of giardia Iamblia

Answer 37

diarrhoea, flatulence, abdominal cramps, epigastric pain, nausea steatorrhea and weight loss may develop

Question 38

how is giardia Iamblia diagnosed

Answer 38

stool examination for ova and parasites

Question 39

how is giardia iamblia treated

Answer 39

metronidazole 1 week

Question 40

what other parasites can cause malabsorption

Answer 40

coccidial, stronglyoides

Question 41

what are the symptoms of small bowel bacterial overgrowth

Answer 41

diarrhoea, steatorrhoea, macrocytic anemia (B12)

Question 42

what bacteria commonly cause a small bowel overgrowth

Answer 42

E.Coli or bacteroides

Question 43

what can predispose someone to a small bowl overgrowth

Answer 43

diverticula, fistulas and strictures relating to crohns, bypass surgeries, functional stasis

Question 44

what is a small bowl overgrowth

Answer 44

the presence of excess bacteria in the intestine

Question 45

how is a small bowel overgrowth diagnosed

Answer 45

low cobalamin and high folate levels, schillling test

Question 46

how is small bowel bacterial overgrowth breated

Answer 46

surgical correction of an anatomical loop, tetracyclines 2-3 weeks

Question 47

what past medical history would make you think malabsorption

Answer 47

gastric or small bowel resection, gastrointestinal diversion (bariatric), radiation exposure, travel

Question 48

what are the gastrointestinal symptoms of malabsorption

Answer 48

diarrhoea, weight loss, flatulence, abdominal bleeding, abdominal cramps, pain, oedema

Question 49

what signs could be found on examination in malabsorption

Answer 49

easy bruising, acrodermatits enteropathica, dermatitis herpetiformis, glossitis and angular stomatitis, spooning of the nails,

Question 50

what can cause easy bruising

Answer 50

vitamin C def 'scurvy', vit k def

Question 51

what causes acrodermatits enteropathica

Answer 51

autosomal recessive, impaired zinc uptake

Question 52

what causes dermatitis herpetiformis

Answer 52

may indicate coeliac disease

Question 53

what cause glossitis and angular stomatitis

Answer 53

B vit and iron def

Question 54

what causes spooning of the nails

Answer 54

iron def (thyroid)

Question 55

what are the base line investigations in malabsorption

Answer 55

``` full blood count (anaemic, vit def) coagulation (vit k test) liver function test, albulmin, calcium/ magnesium, stool culture ```

Question 56

what anatomic investigations can be done in malabsorption

Answer 56

endoscopy, imaging

Question 57

how is malabsorption treated

Answer 57

treat underlying cause, replace the deficiency, support nutritionally,