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Flashcards in Small Intestine Deck (68):
1

What are the 3 mechanisms of malabsorption

Structural disorder
Mucosal disorder
Abnormal luminal digestion

2

What are the general clinical features of malabsorption

Malaise
Anorexia
abdominal bloating
diarrhoea
weight loos

3

What are some specific clinical features of malabsorption

Steatorrhoea (fat malabsorption)
Oedema ascites (protein malabsorption)
Skin rash (Zn or Vit B malabsorption)
Cheilitis, glossitis (vitamin B malabsorption)
Neuropathy, psychological effects (vit B12 malabsorption)
Night blindness (vit A malabsorption)
Bruising (vit K or vit C malabsorption)
Bone pain, myopathy, oesteoporosis (vit D malabsorption)

4

What are the 3 aims of investigating malabsorption

To establish the condition
To identify the site of abnormality
To identify the severity

5

What is short bowel syndrome

This is typically when there is

6

When does short bowel syndrome occur

When there is insufficient functioning small intestine to allow normal digestion and absorption

7

What are some causes of short bowel syndrome (intestinal failure)

Extensive surgery
Crohn's disease
Mesenteric ischaemia
Radiation damage
Volvulus
Congenital abnormalities in children

8

What is the short term management of SBS

Correct malnutrition
Reduce gut secretions (PPI, codeine, loperamide)

9

What is the long term management of SBS

Monitor nutrition and ensure adequate calorie intake
Monitor hydration status
Replace vitamins and mineral
Reduce gut secretions
Treat small intestinal bacterial overgrowth
Cholecystectomy if gallstones develop
Small bowel transplantation

10

What is Ceoliac disease

An immune mediated disorder resulting in small intestinal villous atrophy which resolves on gluten withdrawal from the diet

11

What is the main toxic antigenic component of fluten

Alpha - gliadin

12

What does the protein in gluten cause

A T cell mediated inflammatory response of the small bowel

13

What is the prevalence of Coeliac disease in the UK

1:200

14

What are clinical features of Coeliac disease

Failure to thrive at weaning time (infants)
Abdominal pain / bloating
Lethargy
Anaemia
Diarrhoea or constipation

15

What is Coeliac disease linked to

HLA-DQ2

16

What is coeliac disease often linked to

Other autoimmune diseases such as dematitis herpetiformis, insulin dependent diabetes, thyroid disease, primary biliary cirrhosis

17

What are the investigations to confirm the fiagnosis

Duodenal biopsy is GOLD STANDARD

18

What would be seen on a duodenum biopsy in someone with Coeliac disease

Villous atrophy
Crypt hyperplasia
Intraepithelial lymphocytosis

19

What antibody needs to be tested for in Coeliac disease

IgA antibodies to Tissue transglutaminase (TTG)

20

Why might a patient get a false negative result for IgA

IgA deficiency

21

What should be tested when investigating the consequences of Coeliac disease

FBC and blood film
Haematinincs
Clotting screen
Bone investigation

22

What is the management for Coeliac Disease

Life long gluten-free diet to prevent the ongoing antigen provocation of the inflammatory response
Correct deificencies
Aggressive management of any bone disease

23

What is tropical sprue

A rare condition associated with small intestine villous atrophy and is thought to be post-infectious.

24

Who does tropical spruce normally affect

Residents of tropical countries (not travellers)

25

What are 2 common symptoms of tropical sprue

Diarrhoea and abdominal distension

26

What is the treatment for Tropical sprue

Longterm tetracycline and folic acid

27

What 3 things does colonisation of the small intestine by colonic flora result in

Deconjugating bile salts (diarrhoea)
Metabolising vitamin B12 (anaemia)
Metabolising carbohydrate (resulting in calorie malnutrition and halitosis)

28

What 2 investigations are carried out for the condition of small intestinal bacterial overgrowth?

Jejunal aspirate
Hydrogen breath test after ingesting glucose or lactulose

29

How is the cause of small intestinal bacterial overgrowth investigated

Small bowel radiology (identifies structural or communication abnormalities )

30

What is a complication of Small intestinal bacterial overgrowth investigated

Low B12 and normal folate

31

What 3 things are required in the management of small intestinal bacterial overgrowth

Antibiotics directed towards colonic flora
Replace vitamin B12
Definiteive treatment if poosible - surgery or prokinetics

32

What is bile acid malabsorption characterised by

Postprandial diarrhoea due to osmotic effect of bile salts in the colon or steatorrhoea

33

If bile acid malabsorption is a secondary abnormality, what is it most commonly due to

Crohn's disease
ileal resection
intestinal failure

34

What is teh treatment for bile acid malabsorption

Cholestyramine - a bile acid sequestrant

35

What is Whipple's disease

A rare disease characterised by malabsorption, finger clubbing, fevers, skin pigmentation, seronegative large-joint arthropathy

36

How is the diagnosis of Whipple's disease established

By identifying foamy fmacrophagses which stain positive with periodic acid-Schniff on jejunal biopsy

37

What is the treatment for Whipple's disease

Cotrimoxazole or tetracycline for 1 year

38

What is protein-losing enteropathy

Gut loss of protein sufficient to reduce serum albumin

39

How common are small intestine tumours

Very rare - account for

40

What are the 2 important types of small intestine tumours

Carcinoid and lymphoma

41

Describe carcinoid tumours

Slow growing and arise from the appendix, small intestine or rectum

42

When does carcinoid syndrome occur

Only if the tumour metastasises

43

What is carcinoid syndrome caused by

Systemic release of serotonn, prostaglandins and bradykinins

44

How are carcinoid tumours diagnosed

By measuring urinary 5-HIAA

45

What is the treatment for carcinoid tumours

Surgical resection

46

What are 3 main presentations of carcinoid syndrome

Wheezing
Flushing
Diarrhoea

47

What is the diagnostic test for lymphoma

Abdominal CT

48

What is the treatment of choice for lymphoma

Surgical resection

49

What is immunoproliferative small intestinal disease

A rare condition also known as alpha heavy chain disease

50

Who does immunoproliferative small intestinal disease normally affect

Mediterranean and Arab races

51

How do patients with immunoproliferative small intestinal disease typically present

With diarrhoea
malabsorption
clubbing
weight loss

52

What shows the alpha heavy chains in immunoproliferative small intestinal disease

Serum electrophoresis

53

What is the treatment for immunoproliferative small intestinal disease

Long term antibiotics
Only some need chemotherapy

54

What is more common: single polyp or multiple polyps

Multiple polyps

55

What are the 3 types of multiple polyps

Nodular lymphoid hyperplasia
Hamartomas
Andeomatous

56

What is chronic intestinal pseudo-obstruction

Refers to a dpectrum of rare disorders characterised by the signs and symptoms of intestinal obstruction in the absence of true obstruction

57

What is required to determine the diagnosis of chronic intestinal pseudoobstruction

Radiological demonstation of a dilated proximal small bowel

58

What is Meckel's diverticulum

The commonest congenital gut abnormality resulting from failure to close the vitelline duct

59

If a patient is symptomatic with Meckel's diverticulum, at what age would they present?

Before the age of 2

60

Males are twice as likely to be affected. True or False

True

61

What are the classic symptoms of Meckel's diverticulum

Painless melaena with intestinal obstruction or intussusception being rare

62

How is Meckel's diverticulum diagnosed

Using a Meckel's scan - injecting a radioisotope which is taken up by ectopic parietal cells

63

Who is most likely to have hypolactasia

Africans and Asians

64

What might secondary causes of lactase deficiency result in

Osmotic diarrhoea, abdominal pain
borborygmi after eating milk products
Flatulence

65

How is diagnosis of lactase deficiency made

Using a lactose substrate hydrogen breath test

66

What is the treatment for lactase deficiency

Minimising milk products

67

In food allergy, what type of hypersensitivity reaction occurs

Type 1

68

What is the treatment for food allergy

Dietary avoidance