Colon Disease

Question 0

Where do ganglion cells in the GI tract derive from

Answer 0

Neural crest – > give rise to ganglion cells – > descend into bowel wall

Question 1

What disease and gene is Hirschsprung’s disease associated with

Answer 1

Down syndrome

RET gene

Question 2

Where are meissners and Auerbach plexuses?

What do they function as?

Answer 2

Meisner is = @ submucosa
Regulate BF, secretion, absorption

Auerbach plexus = @ Muscularis propria between inner circular+ outer longitudinal layer
Mobility peristalsis + relaxation

Question 3

Where does hirschprung disease usually occur?

Answer 3

Rectum/distal sigmoid colon

Question 4

How does Hirschsprung disease affects the two plexuses?

Answer 4

Lack ganglion cells in MEISSNERS + AUERBACH plexus – >

decreased peristalsis – >
can’t Pass stool properly + ⬇️ relaxation @ rectum

– >Can’t remove stool from body

Question 5

What are the clinical features of Hirschsprung’s disease based on?

Answer 5

Obstruction

Question 6

What are the clinical signs and symptoms of Hirschsprung disease

Answer 6

Abdominal distension
Bilious emesis
Can't pass meconium
Dilatate colon proximal to Aganglionic rectum
Empty vault @ DRE

Question 7

What Hallmark high-yield instrument do you use to make a diagnosis of Hirschsprung disease?

Treatment?

Answer 7

Rectal suction biopsy – >

shows aganglionic area of cells

Bowel recection that is aganglionic

Question 8

What is a diverticula of the GI tract

Answer 8

Blind outpouching @ GI tract that communicates with gut lumen–
Pseudodiverticula/FALSE diverticulum i.e.

Only mucosa + submucosa through muscularis propria/externa, NOT entire wall

Question 9

What’s the risk factor associated with diverticula

Answer 9

Constipation/low fibre diet – >increased wall stress – >

Push mucosa + submucosa through muscularis propria/extern

Question 10

Histologically and macroscopically where do you diverticula MOST OFTEN occur?

Answer 10

Histologically: arise + weak point in colonic wall where Vasa Recta traverse muscularis propria

Macroscopically MOST OFTEN @sigmoid colon

Question 11

What are the three complications of diverticular in the GI tract

Answer 11

1.diverticulum into faeces – Hematochezia

2 .diverticulitis : Faeces obstruct diverticula @Wall inflammation = diverticulitis –> perforate –>

PERITONITIS
ABSCESS
BOWEL STENOSIS
3. FISTULA - colovesicular fistula

Question 12

Patient presents with air and stool in his urine. What’s the diagnosis?

Answer 12

Colovesicular fistula due to diverticulitis

Question 13

What does a patient with diverticulitis present with

Answer 13

Fever Leukocytosis LLQ pain

Question 14

What is angiodysplasia

Answer 14

Acquired malformation of mucosal + submucosal capillary beds usually @

Cecum + RIGHT colon

Question 15

Patient presents with high stress + left colon.
Diff patient presents with high stress + right colon.

What are their diagnoses

Answer 15

Left: diverticuli – > hematoCHEZIA

Right: ANGIODYSPLASIA – >hematoCHEZIA

Question 16

What is hereditary haemorrhagic ttelangiectasia

Answer 16

Autosomal dominant

Dilated thin-walled blood vessels

that haemorrhage

@nasal pharynx + GI tract

Question 17

Where does ischaemic colitis okay are usually. What is the most common cause?

Answer 17

Atherosclerosis @ SMA – > decreased blood flow – >

Ischaemia @ splenic flexure

due to watershed area and furthest away from blood supply

Question 18

Explain post prandial pain in ischaemic colitis

Answer 18

Eat – >increased energy requirement of gut – >

Atherosclerosis = ⬇️ blood flow – > not enough blood to splenic flexure = post-prandial pain – >

lose weight due to pain when eating