GI 229&237 Nutrition and Chronic Diarrhoea

Question 1

What is short bowel syndrome?

Answer 1

A state of malabsorption and malnutrition that occurs following massive anatomical or functional loss of the SI

Question 2

What is necrotizing enterocolitis?

Answer 2

Ischaemia and necrosis of the SI in neonates causing 22-50% of SBS - a surgical emergency in neonates

Question 3

What is intusseption of the bowel?

Answer 3

Part of the intestine folds into another part - presents in childhood

Question 4

What is the function of the ileocaecal valve?

Answer 4

To slow transit time and to prevent bacterial reflux from the large intestine to the small

Question 5

What happens in ileal adaptation?

Answer 5

Usually when there has been a jejunum resection

epithelial hyperplasia within 24hours, with villi changes resulting in increased macronutrient absorption

Question 6

What must be given after jejenal resection?

Answer 6

Enteral feeding as it stimulates ileal adaptation

containing: arginine, TG’s, glutamine and AA’s

Question 7

What diet is recommended after jejenal resection?

Answer 7

Diet higher in fat and protein

Question 8

What are the main complications that must be managed with an ileal resection?

Answer 8

Massive fluid and electrolyte loss due to malabsorption of bile salts and Vitamin B12

Question 9

What are some complications of Short Bowel Syndrome?

Answer 9

Hypergastrinaemia, malabsorption of bile acids, therefore fat soluble vitamins, clotting disorders, osteoporosis and nephrolithiasis

Question 10

What is hypergastrinaemia and why does it occur in SBS?

Answer 10

(mostly in jejenal resection) the negative feedback mechanism for inhibiting gastrin secretion has been removed
can lead to oesophagitis or PUD but is often only transient

Question 11

Why can gallstones occur in SBS?

Answer 11

A decreased bile acid:cholesterol ratio and stasis allowing gallstone formation

Question 12

Why can nephrolithiasis occur in SBS?

Answer 12

Bile salts in the colon stimulates increased oxalate absorption giving rise to renal oxalate stones

Question 13

What are the indications for enteral feeding?

Answer 13

Functioning gut but cannot meet the nutritional requirements with normal food
3 months of >10% unintentional weight loss and a hypermetabolic state e.g. sepsis or trauma

Question 14

What are the indications for parenteral feeding?

Answer 14

Non-functioning gut, gut rest needed, >7 days inadequate nutrition
e.g. in severe pancreatitis, post chemo, IBD, intestinal atresia and other motility disorders
Use short term only (2/52)

Question 15

Explain refeeding syndrome

Answer 15

When a state of starvation is quickly reversed the catabolic processes and state of gylcogenolysis and gluconeogenesis switch to anabolic. There is sudden increase in insulin in response to feeding leading to increased protein and glycogen synthesis
This leads to rapid uptake of vitamins into cells with Na and water retention
Can be fatal due to mineral and electrolyte deficiencys

Question 16

What minerals is there rapid uptake of in refeeding and therefore what problems?

Answer 16

hypoPhosphate = tissue hypoxia
hypomagnesium
hypokalaemia = cardiac dysrhythmias
decreased thiamine = confusion
Na+/water = oedema 
there is also thrombocytopaenia

Question 17

What are the risk factors for refeeding syndrome?

Answer 17

One of:
BMI 15% weight loss in 3-6 months
Low minerals to begin with

Two of:
BMI 10% in 3-6months
intake decreaed in >5/7
Alcohol/drug abuse

Question 18

How do you prevent refeeding?

Answer 18

Decrease rate of feeding initially
Vitamin B for the 1st 10 days
Supplement electrolytes assessing daily and comparing to baseline
If refeeding occurs then slow feeding rate

Question 19

What do you get with a Vitamin A deficiency?

Answer 19

compromised mucosa, night blindness and benign intracranial HTN

Question 20

What do you get with a Vitamin D deficiency?

Answer 20

Ricketts/Osteomalacia

Question 21

What do you get with a Vitamin E deficiency?

Answer 21

Increased susceptibility to oxidant stress th. CVS disease
Haemolysis
Neurological symptoms

Question 22

What do you get with a Vitamin K deficiency?

Answer 22

Coagulopathy - prolonged PT

Question 23

What happens in lactose intolerance?

Answer 23

There is a lack of digestion of lactose by brush border enzymes resulting in its accumulation in the lumen - has an osmotic effect leading to diarrhoea and it also ferments in the intestine leading to gas, bloating and acidic stools

Question 24

How would you investigate a suspected lactose intolerance?

Answer 24

Lactose breath test - give lactose to ingest then if there is an intolerance there will be increase hydrogen

Question 25

What are some causes of lactase deficiency?

Answer 25

Primary - can develop later, often after 5 years of age is an AR disorder
Congenital extremely rare and infant fails to thrive
Secondary to mucosal injury - often transient

Question 26

What is the breakdown of Lactose?

Answer 26

By lactase into glucose and galactose

Question 27

What does the SGLT transporter do?

Answer 27

Transports glucose and galactose coupled with Na+

Question 28

Where is CCK released from?

Answer 28

I cells in duodenum and jejenum

Question 29

Where does CCK act on and what are its actions?

Answer 29

Pancreas: increase enzyme secretion
Gallbladder: Contraction and sphincter of oddi relaxation

Question 30

What are the actions of Gastrin?

Answer 30

Parietal cells: H+ release

Question 31

Where is glucagon released from?

Answer 31

alpha cells of pancreas (islets of langerhans)

Question 32

What is the action of glucagon?

Answer 32

Opposes insulin: increase production of glucose and breakdown of glycogen

Question 33

What is ghrelin and where is it released from?

Answer 33

Hormone released from stomach that stimulates appetite

Question 34

Describe somatostatin

Answer 34

Released from stomach and D cells in pancreas - inhibits secretion and action of most hormones!

Question 35

What is the action of guanylin?

Answer 35

Stimulates fluid absorption from the SI/LI

Question 36

Where is VIP released rom?

Answer 36

ENS neurones

Question 37

What is the action of VIP?

Answer 37

SI/Pancreas = increased secretions
SI = relaxes smooth muscle