Small Intestinal Disorders and Investigations

Question 1

What is digestion?

Answer 1

Breaking down of food into its components

Question 2

What is absorption?

Answer 2

Passage of nutrients into the body

Question 3

What are the functions of the small intestine?

Answer 3

Digestion

Absorption

Endocrine and neuronal control (flow of material from stomach to colon)

Barrier functions

Question 4

When is the full length of the small intestine reached?

Answer 4

Usually by age 11

Question 5

What is the average length of the small intestine?

Answer 5

2.5-4.5m

Question 6

What allows the small intestine to have such as large surface area?

Answer 6

Villous architecture

Constant turnover of cells in crypts and villi

Question 7

Why does the small intestine have a low bacterial population?

Answer 7

Toxic environment due to digestive enzymes, bile salts and IgA

Question 8

What does maintaining control of digestion require?

Answer 8

Lots of fluid

Controlled hydroplysis to avoid fluid shifts

Sophisticated control of motility

Absorption against gradients

Onwards processing in the liver

Question 9

What enzymes are in the stomach for digestion?

Answer 9

Salivary amylase

Pepsin

Question 10

Why must digestion in the stomach be controlled?

Answer 10

Avoid osmotic shifts

Question 11

What are proteins broken down into?

Answer 11

Oligopeotides and amino acids

Question 12

What enzymes control the breakdown of protein?

Answer 12

Trypsin and chymotrypsin

Question 13

What enzyme controls the breakdown of fat?

Answer 13

Pancreatic lipase

Question 14

What is fat broken down into?

Answer 14

Glycerol and free fatty acids

Question 15

What enzyme controls carbohydrate breakdown?

Answer 15

Pancreatic amylase

Question 16

What does pancreatic amylase break carbohydrates down into?

Answer 16

Disaccharides

Question 17

What does the final digestion of carbohydrates?

Answer 17

Brush border disaccharidase

Question 18

What are symptoms of small intestine disorders?

Answer 18

Weight loss

Increased appetite

Diarrhoea

Sometimes steatorrhoea

Bloating

Fatigue

Question 19

What is steatohoea caused by?

Answer 19

Fat malabsorption

Question 20

What is poo like for someone who has steatorrhoea?

Answer 20

High fat content

Stool less dense and floats

Pale

Foul smeeling

May leave an oily mark or oil droplets

Question 21

What are signs of small intestinal disorders?

Answer 21

Signs of weight loss such as low or falling BMI

Question 22

What are some examples of possible vitamin/mineral deficiencies?

Answer 22

Iron

B₁₂

Ca²⁺, Mg²⁺

D

B₉ (folate)

A

K

B complex

C

Question 24

What are signs of calcium, magnesium and vitamin D deficiency?

Answer 24

Tatany

Osteomalacia

Question 25

What is a sign of vitamin A deficiency?

Answer 25

Night blindness

Question 26

What is a sign of vitamin K deficiency?

Answer 26

Raised PTR

Question 27

What are signs of thiamine deficiency?

Answer 27

Memory, dementia

Question 28

What are signs of niacin deficiency?

Answer 28

Dermatitis, unexplained heart failure

Question 29

What is a sign of vitamin C deficiency?

Answer 29

Scurvy

Question 30

What is clubbing a sign of?

Answer 30

Coeliac disease Crohn's disease

Question 31

What is scleroderma a sign of?

Answer 31

Systemic sclerosis

Question 32

What is aphthous ulceration a sign of?

Answer 32

Coeliac disease Crohn's disease

Question 33

What is dermatitis herpetiformis?

Answer 33

Cutaneous manifestation of coeliac disease: blistering intensely itchy scalp, shoulders, elbows, knees IgA deposits on skin

Question 34

What tests can be done to look at the structure of the small bowel?

Answer 34

Endoscopy Barium study CT scan MRI enterography Capsule enterography White cell scan Bacterial overgrowth tests (H₂ breath test, or culture a duodenal or jejunal aspirate)

Question 35

What is measured in an H₂ breath test?

Answer 35

Lactulose or glucose substrate

Question 36

What tests can be done for small intestine function?

Answer 36

Very few compared to structure

Question 37

Are IgA or IgG tests more reliable?

Answer 37

IgA

Question 38

Who often has selective IgA deficiency?

Answer 38

Coeliacs (3%)

Question 39

What are confirmational tests for coeliac disease?

Answer 39

Distal duodenal biopsy (looking for villous atrophy and HLA status)

Question 40

What is coeliac disease?

Answer 40

Autoimmune disease where the small intestine becomes inflammed

Question 41

What is gliadin?

Answer 41

Class of proteins present in wheat, rye and barley

Question 42

What is gliadin a component of?

Answer 42

Gluten

Question 43

What is the pathology of gliadin in people with Coeliac disease?

Answer 43

Produces an inflammatory response Partial or subtotal villous atrophy Increased intra-epithelial lymphocytes

Question 44

What is done to diagnose people allergic to gliadin

Answer 44

Distal duodenal biopsy Serology (anti endomysial IgA, anti-tissue transglutaminase)

Question 46

Though what tissue does gliadin produce an inflammatory response through?

Answer 46

Thought to be transglutaminase

Question 47

What is the treatment for people allergic to gliadin?

Answer 47

Withdraw gluten Refer to state registered dietitian

Question 48

What are some associated conditions with gliadin allergy?

Answer 48

Dermatitis herpetiformis IDDM Autoimmune thyroid disease Primary biliary cirrhosis Autoimmune hepatitis

Question 49

What are some complications of gliadin allergy?

Answer 49

Refractory coeliac disease Small bowel lymphoma Oesophageal carcinoma Colon cancer Small bowel adenocarcinoma

Question 50

What are different categories of causes of malabsorption?

Answer 50

Inflammation Infection Infiltration Impaired motility Iatrogenic Pancreatic

Question 51

What are some diseases that cause malabsorption through inflammation?

Answer 51

Coeliac disease Crohn's disease

Question 52

What are some infections that can cause malabsorption?

Answer 52

Tropical sprue HIV Giardia lamblia Whipple's disease

Question 53

What is an infiltrative cause of malabsorption?

Answer 53

Amyloid

Question 54

What are diseases that can cause impaired motility leading to malabsorption?

Answer 54

Systemic sclerosis Diabetes Pesudo-obstruction

Question 55

What are some iatrogenic causes of malabsorption?

Answer 55

Gastric surgery Short bowel syndrome Radiation

Question 56

What are some pancreatic causes of malabsorption?

Answer 56

Chronic pancreatitis Cystic fibrosis

Question 57

Small bowel overgrowth can occur in any condition that affects what?

Answer 57

Motility Gut structure Immunity

Question 58

What is small bowel overgrowth diagnosed by?

Answer 58

H₂ breath test

Question 59

What is the treatment for small bowel obergrowth?

Answer 59

Rotating antibiotics