Lower GI Tract-Non-Neoplastic

Question 1

Aetiology of peptic ulcers

Answer 1

ACID
H. PYLORI

Genetics
Triggers: certain foods, alcohol, smoking, stress

Rarer: NSAIDS, Crohn’s, steroids, Zollinger Ellison syndrome (carcinoid tumour producing gastrin)

Question 2

Complications of peptic ulcer disease

Answer 2

Blood loss (vomiting, meleana, anaemia)

Gastric outlet obstruction

Perforation/infection

Malignancy: rare in duodenum, SEEN IN STOMACH

Question 3

Define coeliac disease

Answer 3

Immunologically mediated chronic inflammatory disease

Intolerance to gliadin part of gluten (storage protein of cereal etc)

Question 4

Key histology features of coeliac disease

Answer 4

Increased intraepithelial lymphocytes

VILLOUS ATROPHY

Plasmacytosis in lamina propria

Question 5

Genetics of coeliac?

Answer 5

Specific HLA haplotypes and gerographical clustering

Question 6

Diagnosis of coeliac disease? (serology, biopsy, clinical)

Answer 6

Serology: Anti TTG, Anti EMA

Biopsy: OGD, villous atrophy

CLinical: GLuten withdrawl: improvement in symptoms

Question 7

Associations with coeliac disease

Answer 7

Autoimmune diseases with same HLA haplotypes: DM type 1 and hypothyroidism

Dermatitis herpetiformis

Question 8

WHich cancer is linked to coeliac disease?

Answer 8

Small bowel lymphoma: Enteropathy associated T cell NHL

Poor prognosis

Also increased risks of other GI cancers

Question 9

Investigations for viral gastroenteritis

Answer 9

Stool culture/PCR

SEE SCBP MICROBIOLOGY FOR DISEASE DETAILS

Question 10

How does mycobacteria affect the bowel?

Answer 10

TB of the bowel, or atypical infections in small bowel in AIDS patients

Question 11

Describe Whipple’s disease

Answer 11

Tropheryma whippella (PAS +ve)

found in duodenal biopsy alongside symptoms of malabsorption, joint pain, neurological symptoms

Question 12

Types of viral gastroenteritis

Answer 12

SRSVS eg Norwalk

Rotaviruses in children

Adenovirus (linked with lymphoid hyperplasia and intusssusception)

Enterovirus: polio, Cox A and B

HIB: cryptosporidiosis, girdia lamblia, CMV, atypical mycobacteria

Question 13

Examples of protozal GI infections?

Answer 13

Giardia (dirty water)

Cryptosporidia (immunosuppressed pts)

Amoebae colitis (followng trip abroad, may cause life threatening HAEMORRHAGIC ENTEROCOLITIS)

Question 14

Biopsy diagnosis: Schistosome in a granuloma in a colonic biopsy

Answer 14

Schistosomiasis

Question 15

Epidemiology of IBD

Answer 15

Adolescents

Second peak in older adults

F>M

Developed world>undeveloped

Question 16

Aetiology of IBD

Answer 16

Idiopathic: no specific cause identified

Question 17

Polymorphisms in NOD1 gene linked ot which IBD?

Answer 17

Crohn’s

Question 18

Granulomas present in which IBD?

Answer 18

Crohn’s

Also has fissure ulceration

Question 19

Fat wrapping in which IBD?

Answer 19

Crohn’s

Fat around bowel seems to be drawn in

Question 20

Complications of Crohn’s?

Answer 20

Fistualae
Sinuses
Strictures

Risk of lymphomas with immunosuppression and SCC

Question 21

Key complications of ulcerative colitis?

Answer 21

Toxic megacolon

Increased risk of colorectal cancer

Question 22

What causes small bowel ileus?

Answer 22

Atonic small bowel associated with fluid imbalance

Question 23

Describe Meckel’s diverticulum (2 rule)

Answer 23

2% of population

2 inches long 2 feet proximal to ileocaecal valve

Question 24

Pathogenesis of appendicitis

Answer 24

Faecolith, foreign body, lymphoid hyperplasia, endometriosis, tumour

Venous outflow compromised, mucosal ulceration, secondary infection and transmural inflammation

Question 25

Cancers related to appendicitis

Answer 25

Low grade appendiceal mucinous neoplasm (LAMN)

Carcinoid tumours

Question 26

Where does diverticular disease occur?

Answer 26

These are commonest in the sigmoid colon, but can occur in other parts of the colon, and they occur
between the taenia coli, and are associated with a thickened circular layer of muscularis propria in
between the diverticul

Question 27

Blood supply to GIT?

Answer 27

Coeliac, superior and inferior mesenteric

SM and IM arteries form arcades

Watershed zones are susceptbile to ischaemia (splenic flexure, junction between SM and IM arteries)

Question 28

Variations in severity of small bowel ischaemia

Answer 28

Acute arterial insufficiency or venous obstruction: mucosal ulceration

More severe/longstanding lack of supply: typically thin walled, dusky loops of small bowel

Repeated episodes of damage: Iscahemic colitis with strictures