Small intestinal disorders and investigation

Question 1

Functions of the small intestine? (4)

Answer 1

Digestion

Absorption

Barrier functions

Endocrine and neuronal control functions - Controlling the flow of material from the stomach to the colon and motility

Question 2

Why is the breakdown process (digestion) controlled?

Answer 2

to avoid osmotic shifts

Question 3

Where does the final hydrolysis and absorption occur?

Answer 3

at brush border

Question 4

Proteins are broken down into what?

Answer 4

oligopeptides and amino acids

Question 5

Name 2 enzymes involved in digestion process

Answer 5

trypsin

chymotrypsin

Question 6

How is fat digested?

Answer 6

pancreatic lipase

absorption of glycerol and free fatty acids

via lacteal and lymphatic system

Question 7

How are carbohydrates digested?

Answer 7

Pancreatic amylase

Breakdown to disaccharides

Final digestion by brush border disaccharidase

Question 8

What are the barrier functions of the small intestine

Answer 8

Low bacterial population
so has a toxic environment
- Digestive enzymes
- Bile salts
- Presence of IgA etc

Maintaining a barrier against pathogens

• Immune sampling
• Monitoring the presence of pathogens
• Translocation of Bacteria
• Gut Associated Lymphoid Tissue (GALT)

Question 9

Investigations looking at the structure of the small intestine (4)

Answer 9

Small bowel biopsy
- Endoscopy

CT Scan

MRI enterography

Capsule enterography - image using pill camera

Question 10

Tests for bacterial overgrowth? (2)

Answer 10

H2 Breath test

• Lactulose or glucose substrate
• Very unreliable

Culture a duodenal or jejunal aspirate

Question 11

Symptoms associated with small bowel diseases (5)

Answer 11

Weight Loss

Increased appetite

Diarrhoea

• Usually watery
• Sometimes steatorrhoea

Bloating

Fatigue

Question 12

Signs of deficiencies:

Iron
Vitamin A
Vitamin C
Vit B complex

Answer 12

Iron - B12 level, Folate

Vit A - Night blindness

Vit C - scurvy

Vit B complex - thiamine (memory, dementia) or Niacin (dermatitis, unexplained heart failure)

Question 13

Clubbing can be a sign of what diseases

Answer 13

coeliac disease

Crohn’s

Question 14

Scleroderma (scarring and thickening of the tissue) can be a sign of which disease

Answer 14

systemic sclerosis

Question 15

Aphthous ulceration

can be a sign of what diseases

Answer 15

coeliac disease

Crohn’s

Question 16

What is dermatitis herpetiformis

Answer 16

Cutaneous manifestation of coeliac disease

• Blistering
• Intensely itchy
• Scalp, shoulders, elbows, knees
• IgA deposit in skin

Question 17

How common is coeliac disease in UK

Answer 17

1: 111 screening
1: 300 clinical diagnosis

Question 18

Tests for coeliac disease

Answer 18

Serology is approximately
90% specific
90% sensitive

IgA tests more reliable than IgG
But only if you make IgA
A significant number of people don’t

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

Therefore, always check the total plasma IgA as well

Question 19

What is the gold standard confirmatory test for coeliac disease?

Answer 19

distal duodenal biopsy - may show villous atrophy

Question 20

Genes that are associated with coeliac disease?

Answer 20

HLA DQ2 or DQ8

30% of the population have this though, not just coeliac’s however 97% of coeliac’s do

Question 21

What is Gliadin

Answer 21

a fraction of gluten found in Wheat, Rye and Barley

people may be sensitive to gliadin

Question 22

Treatment for coeliac’s disease

Answer 22

Withdraw Gluten

However, Wheat is used widely in commercial food manufacture

Diet is life long

MUST refer to a state registered dietitian

Question 23

What are some other conditions that are associated with Coeliac’s disease (9)

Answer 23

Dermatitis herpetiformis

Type 1 DM

Autoimmune thyroid disease

Autoimmune hepatitis

Primary Biliary Cholangitis

Autoimmune gastritis

Sjogren’s syndrome - autoimmune disease that attacks glands that secrete tears + saliva

IgA deficiency

Down’s syndrome

Question 24

Complications with coeliac disease (5)

Answer 24

Refractory coeliac disease - persistent or recurrent malabsorptive symptoms and villous atrophy despite strict adherence to a gluten-free diet

Small bowel lymphoma

Oesophageal carcinoma

Colon cancer

Small bowel adenocarcinoma

Question 25

What is tropical sprue?

Answer 25

a malabsorption disease commonly found in tropical regions, marked with abnormal flattening of the villi and inflammation of the lining of the small intestine.

Question 26

What is Giardia lamblie? How is it transmitted? Drug treatment used?

Answer 26

a unicellular parasite found in contaminated water

colonises and reproduces in the small intestine, causing giardiasis

responds to drug Metronidazole

Question 27

What is Whipple’s disease?

Answer 27

rare bacterial infection common in middle aged men

Has skin, brain, joints and cardiac effects

It interferes with normal digestion and nutrient absorption

Tropheryma whippelii is the causative organism

weight loss and abdominal pain common

Question 28

What is the hallmark of Whipple’s disease?

Answer 28

the accrual of periodic-acid Schiff (PAS)-stained foamy macrophages in the villi

Question 29

Small bowel problems caused by medical examination/interference

Answer 29

Gastric surgery

Short bowel syndrome

Radiation

Question 30

When can small bowel bacterial overgrowth occur?

Answer 30

in any condition that affects:-
Motility
Gut structure
Immunity

Question 31

Treatment options for bacterial overgrowth?

Answer 31

rotating antibiotics:- 
- Metronidazole
- Tetracycline
- Amoxicillin
Each for 2 weeks

vitamin and nutritional supplements too

Question 32

Main causes of small intestinal problems in the UK

Answer 32

Chron’s

Coeliac disease