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 barrier functions?

Answer 3

Regulating what stays in and gets out

Question 4

what are endocrine and neuronal control functions of the small intestine?

Answer 4

Controlling the flow of material from the stomach to the colon
Motility

Question 5

What are the functions of the small intestine?

Answer 5

Digestion

Absorption

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

Barrier functions

Question 6

When is the full length of the small intestine reached?

Answer 6

Usually by age 11

Question 7

what are the functions of digestion?

Answer 7

Decontaminates dirty food
Requires a lot of fluid
Controlled hydrolysis to avoid fluid shifts
Sophisticated control of motility
Absorption against gradients
Onward processing in the liver

Question 8

where does digestion commence?

Answer 8

in the stomach

Question 10

what causes digestion in the stomach?

Answer 10

Salivary amylase
Pepsin
Controlled breakdown to avoid osmotic shifts

Question 11

how are proteins digested?

Answer 11

Broken down to oligopeptides & amino acids
Trypsin, chymotrypsin
Final hydrolysis and absorption at brush border

Question 12

where does final hydrolysis and absorption of proteins occur?

Answer 12

brush border

Question 13

how is fat digested?

Answer 13

Pancreatic lipase
Absorption of glycerol and free fatty acids
via lacteal and lymphatic system

Question 14

how are carbohydrates digested?

Answer 14

Pancreatic amylase
Breakdown to disaccharides
Final digestion by brush border disaccharidase

Question 15

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

Answer 15

Villous architecture

Constant turnover of cells in crypts and villi

Question 16

Why does the small intestine have a low bacterial population?

Answer 16

Toxic environment due to digestive enzymes, bile salts and IgA

Question 17

What does maintaining control of digestion require?

Answer 17

Lots of fluid

Controlled hydroplysis to avoid fluid shifts

Sophisticated control of motility

Absorption against gradients

Onwards processing in the liver

Question 18

What enzymes are in the stomach for digestion?

Answer 18

Salivary amylase

Pepsin

Question 19

Why must digestion in the stomach be controlled?

Answer 19

Avoid osmotic shifts

Question 20

What are proteins broken down into?

Answer 20

Oligopeotides and amino acids

Question 21

What enzymes control the breakdown of protein?

Question 22

are there many small bowel investigations that are tests of structure?

Answer 22

many and various

Question 23

are there many small bowel investigations that are tests of function?

Answer 23

very few

Question 24

what are the tests of structure available for the small intestine?

Answer 24

Small bowel biopsy
Endoscopy

CT Scan

MRI enterography

Capsule enterography

Question 25

what is capsule enterography?

Answer 25

Capsule endoscopy is a procedure that uses a tiny wireless camera to take pictures of your digestive tract. A capsule endoscopy camera sits inside a vitamin-size capsule you swallow. As the capsule travels through your digestive tract, the camera takes thousands of pictures that are transmitted to a recorder you wear on a belt around your waist.

Question 26

what are other assorted tests of the small intestine?

Answer 26

Bacterial overgrowth H2 Breath test Lactulose or glucose substrate Culture a duodenal or jejunal aspirate

Question 27

What enzymes control the breakdown of protein?

Answer 27

Trypsin and chymotrypsin

Question 28

What enzyme controls the breakdown of fat?

Answer 28

pancreatic lipase

Question 29

What is fat broken down into?

Answer 29

Glycerol and free fatty acids

Question 30

What enzyme controls carbohydrate breakdown?

Answer 30

Pancreatic amylase

Question 31

What does pancreatic amylase break carbohydrates down into?

Answer 31

Disaccharides

Question 32

What does the final digestion of carbohydrates?

Answer 32

Brush border disaccharidase

Question 33

What are symptoms of small intestine disorders?

Answer 33

Weight loss Increased appetite Diarrhoea Sometimes steatorrhoea Bloating Fatigue

Question 34

What is steatohoea caused by?

Answer 34

Fat malabsorption

Question 35

What is poo like for someone who has steatorrhoea?

Answer 35

High fat content Stool less dense and floats Pale Foul smeeling May leave an oily mark or oil droplets

Question 36

What are signs of small intestinal disorders?

Answer 36

Signs of weight loss such as low or falling BMI

Question 37

What are some examples of possible vitamin/mineral deficiencies?

Answer 37

Iron B12 Ca2+, Mg2+ D B9 (folate) A K B complex C

Question 38

What is a sign of vitamin A deficiency?

Answer 38

Night blindness

Question 39

What is a sign of vitamin K deficiency?

Answer 39

Raised PTR

Question 40

What are signs of thiamine deficiency?

Answer 40

Memory, dementia

Question 41

What are signs of niacin deficiency?

Answer 41

Dermatitis, unexplained heart failure

Question 42

What is a sign of vitamin C deficiency?

Answer 42

scurvy

Question 43

What is clubbing a sign of?

Answer 43

Coeliac disease Crohn’s disease

Question 44

What is scleroderma a sign of?

Answer 44

Systemic sclerosis

Question 45

What is aphthous ulceration a sign of?

Answer 45

Coeliac disease Crohn’s disease

Question 46

What is dermatitis herpetiformis?

Answer 46

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

Question 47

how common is coeliacs disease?

Answer 47

1:111 in UK on screening data 1:300 clinical diagnosis

Question 48

what are tests done for coeliacs disease?

Answer 48

Serology IgA/IgG tests - IgA more reliable than IgG, only if you make IgA a significant amount of people dont ALWAYs check plasma IgA aswell

Question 49

how common is selective IgA deficiency?

Answer 49

Selective IgA deficiency is relatively common, about 0.1 to 1% of population But 2 to 3% of coeliacs

Question 50

Are IgA or IgG tests more reliable?

Answer 50

IgA

Question 51

Who often has selective IgA deficiency?

Answer 51

Coeliacs (3%)

Question 52

What are confirmational tests for coeliac disease?

Answer 52

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

Question 53

what are the different types of villous atrophy?

Answer 53

Partial Subtotal Total

Question 54

What is coeliac disease?

Answer 54

Autoimmune disease where the small intestine becomes inflammed

Question 55

What is gliadin?

Answer 55

Class of proteins present in wheat, rye and barley

Question 56

What is gliadin a component of?

Answer 56

gluten

Question 57

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

Answer 57

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

Question 58

What is done to diagnose people allergic to gliadin

Answer 58

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

Question 59

is gliadin in rice, maize or oats?

Answer 59

no

Question 60

Though what tissue does gliadin produce an inflammatory response through?

Answer 60

Thought to be transglutaminase

Question 61

what are 97% of coeliacs for their HLA status?

Answer 61

either HLA DQ2 or DQ8

Question 62

What is the treatment for people allergic to gliadin?

Answer 62

Withdraw gluten Refer to state registered dietitian

Question 63

What are some associated conditions with gliadin allergy?

Answer 63

Dermatitis herpetiformis IDDM Autoimmune thyroid disease Autoimmune hepatitis Primary Biliary Cholangitis Autoimmune gastritis Sjogren’s syndrome IgA deficiency Down’s Syndrome

Question 64

What are some complications of gliadin allergy?

Answer 64

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

Question 65

What are different categories of causes of malabsorption?

Answer 65

Inflammation Infection Infiltration Impaired motility Iatrogenic Pancreatic

Question 66

What are some diseases that cause malabsorption through inflammation?

Answer 66

Coeliac disease Crohn’s disease

Question 67

What are some infections that can cause malabsorption?

Answer 67

Tropical sprue HIV Giardia lamblia Whipple’s disease

Question 68

what is giardia lamblia?

Answer 68

Unicellular parasite Contaminated water Responds to Metronidazole Hypogammaglobulinaemia

Question 69

What is an infiltrative cause of malabsorption?

Answer 69

amyloid

Question 70

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

Answer 70

Systemic sclerosis Diabetes Pseudo obstruction

Question 71

What are some iatrogenic causes of malabsorption?

Answer 71

Gastric surgery Short bowel syndrome Radiation

Question 72

What are some pancreatic causes of malabsorption?

Answer 72

Chronic pancreatitis Cystic fibrosis

Question 73

who does whipples disease most commonly affect?

Answer 73

middle aged men

Question 74

what does whipples disease affect?

Answer 74

skin, brain,joints, cardiac effects

Question 75

what are symptoms of whipples disease?

Answer 75

Weight loss Malabsorption Abdominal pain

Question 76

what is the causative organism of whipples disease?

Answer 76

Tropheryma whippelii is the causative organism

Question 77

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

Answer 77

Motility Gut structure Immunity

Question 78

What is small bowel overgrowth diagnosed by?

Answer 78

H2 breath test

Question 79

What is the treatment for small bowel overgrowth?

Answer 79

Rotating antibiotics

Question 80

what are the rotating antibiotics examples, how long should they each be taken for?

Answer 80

Metronidazole Tetracycline Amoxicillin each for two weeks

Question 81

what should be taken alongside rotating antibiotics?

Answer 81

Vitamin and nutritional supplements

Question 82

77 year old man Losing weight Steatorrhoea Recent minor fall with fractured neck of femur Radiologist notes features of osteomalacia what is this man suffering from?

Answer 82

Tests confirm Fat malabsorption Bacterial overgrowth Small bowel study Multiple jejunal diverticula

Question 83

23 year old student Tired ? Losing a little weight Variable stool Bloating PMH Irritable Bowel Syndrome On Examination Thin BMI 20 kg / m2 what is this student suffering from?

Answer 83

Hb 108 MCV 79 A microcytic anaemia Alb 34 Very slightly reduced Corrected Ca2+ 2.05 mmol/l ? Coeliac disease Anti tissue transglutaminase (Anti-TTG) IgA negative [Anti endomysial antibody neg] Plasma IgA 0.1