pathology of the small intestine

Question 1

symptoms of small intestine pathology

Answer 1

pain 
nausea and vomiting 
symptoms of nutrient deficiency 
loss of appetite/loss of weight 
diarrhoea 
constipation 
fever

Question 2

fever as a symptom

Answer 2

infection related pathology

Question 3

signs of small intestinal pathology

Answer 3

tenderness 
abdominal distension 
palpable mass 
haemorrhage 
peritonitis/systemic infection

Question 4

haemorrhage as a sign in small intestine pathology

Answer 4

haematemasis/malena

anaemia/positive faecal occult blood

Question 5

investigations for small bowel pathology

Answer 5

physical examination
imaging - xray, U/S, CT, MRI
lab tests - stool for microbiology, blood for serology
endoscopy

Question 6

hernia

Answer 6

hernia - when a loop bwel gets stuck in a defect in the abdominal wall and becomes incarcerated and vascular supply becomes compromised usually leading to ischaemia

Question 7

adhesions

Answer 7

adhesions - fibrosis usually in a surgical area causing bpowel to stick together abnormally obstructing the lumen of the bowel

Question 8

vovlolus

Answer 8

volvolus - bowel loops on itself and causes luminal obstruction and compromise of the blood supply

Question 9

intussusception

Answer 9

intussusception - more common in children, telescoping of bowel through itself effecting the lumen and the blood supply

Question 10

small bowel obstruction requires

Answer 10

hernia, adhesions, volvolus and intussusception all require surgical intervention to correct themselves

Question 11

meckle’s diverticulum

Answer 11

remnant vitaline duct

viteline duct should regrew but it doesn’t

Question 12

rule of 2 in meckle’s diverticulum

Answer 12

2% of the population
within 2 feet (60cm) of the ileocaecal valve
2 inches ling
x2 as common in males
are most often symptomatic by age 2 - only approx 4% are ever symptomatic

Question 13

ischaemia of the small bowel

Answer 13

can happen due to obstruction
thrombosis/emboli can cause it
congestion of blood causes it to look red

Question 14

coeliac disease

Answer 14

gluten sensitive enteropathy
chronic disorder of the digestive tract
an inability to tolerate glaidinn, the alcohol soluble fraction of gluten
underdiagnosed

Question 15

immunological response to gliadin in coeliac disease

Answer 15

endogenous tissue transglutamidase (TTG) converts gliadin from a neutral to a negatively charged protein
in some people this induces IL-15 in enteric epithelium, leading to proliferation of NK cells and expression of cell surface markers on epithelial cells that cause T cells to attack them
antiglaidin antibodies are frequently found in untreated patients as is IgA to smooth muscle endomysium and TTG
inflammatory mediated damage to enteric epithelial cells, with T cell infiltration, atrophy of villi in small bowel and loss of absorptive surface leads to mal digestion and malabsorption of many nutrients

Question 16

triggers of coeliac disease

Answer 16

triggers are unknown - genes may play an important role

Question 17

pathology og coeliac disease

Answer 17

inflammatory mediated damage to enteric epithelial cells, with T cell infiltration, atrophy of villi in small bowel and loss of absorptive surface leads to mal digestion and malabsorption of many nutrients

Question 18

morphological changes in pathology of coeliac disease

Answer 18

loss of villous height- atrophy
lymphocytes entering epithelial cells and causing damage
more mitotically active epithelial cells as they are trying to regenerate
due to increases mitosis - crypt hyperplasia

Question 19

tissue translgutaminase

Answer 19

tTG
turns gliadin into negatively charged protein
in coeliac patients this leads to cascade of immune signalling leading to epithelial damage
IL-15 causes expression of proteins recruiting NK cells causing cell damage
may also activate B cells to produce antibodies

Question 20

clinical features of coeliac disease

Answer 20

chronic but variable diarrhoea 
steatorrhea 
abdominal bloating and cramps 
flutulence and borborygmus 
weight loss 
fatigue

Question 21

complications of coeliac disease

Answer 21

anaemia 
bleeding disorders 
osteopeniaa 
seizure disorders and neuromusclular irritation due to hypocaalcaemia 
growth restriction/failure to thrive 
amenorrhoea
infertility 
skin disorders - dermatitis herpetiformis 
risk of malignancy

Question 22

diagnosis of coeliac disease

Answer 22

clinical history, serology, endoscopy, histology

Question 23

serology for diagnosis of coeliac disease

Answer 23

anti-tissue transglutaminase antibody
anti-modified or deaminated gliadin antibodies (AGA)
anti-endomysial antibodies (EMA)
anti-reticulin antibodies (ARA)

Question 24

coeliac disease differential diagnosis

Answer 24

other food intolerance/allergies 
Crohn's diseases 
topical sprue 
infections - giardiasis, helicobacter, cryptoosporidium, viruses 
drug reactions - NSIADS, chemotherapy 
immune system abnormalities

Question 25

tropical sprue

Answer 25

causes similar histological changes to coeliacs | only in tropical countries

Question 26

coeliac disease management

Answer 26

strict lifelong gluten free diet vitamin and mineral supplements antti-inflammatory agents for severe intestinal injury close clinical follow up and management for complications

Question 27

autoimmune enteropathy

Answer 27

x-linked disorder characterised by severe persistent diarrhoea seen often in young children intestinal epithelial damage from anti-enterocyte and anti-globlet cell antibodies leads to small intestinal atrophy severe familial form termed IPEX results from gremlin mutation of FOXP3 gene

Question 28

common variable immunodeficiency

Answer 28

one of the most common symptomatic primary immunodeficiencies characterised by los levels of circulating immunoglobulins both genetic and sporadic forms symptoms vary widely and across body systems

Question 29

GI symptoms of common variable immunodeficiency

Answer 29

abdominal pain, bloating, nausea, vomiting, diarrhoea and weight loss signs of malabsorption

Question 30

small bowel histology of common variable immunodeficiency

Answer 30

may appear normal or show non-specific damage | plasma cells are reduced or absent

Question 31

giardia

Answer 31

protozoan infection associated with malabsorption and chronic diarrhoea spread by a feacal contamination of water present on the surface of the mucosa but does not invade the tissue

Question 32

malignancies

Answer 32

adenocarcinoma neuroendocrine tumours gastrointestinal stromal tumours lymphoma

Question 33

GIST

Answer 33

gastrointestinal stromal tumour | composed of mesenchymal cells

Question 34

metastatic melanoma

Answer 34

common metastasis to the small intestine | may cause intussusception