Small Bowel

Question 1

Lymph nodes are found in ___

Answer 1

ileum

Known as Peyer’s patches (gut associated lymphatic tissue)

Question 2

Jejunum vs ileum

Arterial arcades & vasa recta

Answer 2

Jejunum
- Short arterial arcades
- Long vasa recta

Ileum
- Prominent arterial arcades
- Short vasa recta

Question 3

Most common cancers of the small bowel

Answer 3

1st: Neuroendocrine tumours
2nd: Metastatic melanoma

Question 4

Neuroendocrine tumours of the ___ has the most symptoms

Answer 4

Midgut carcinoid

Flushing, diarrhea - high levels of serotonin secretion

Small bowel IO secondary to intense desmoplastic reaction caused by tumour

Question 5

In carcinoid crisis, ___ should be administered

Answer 5

Octreotide - somatostatin analogue

Question 6

What can cause enteric fistulas to form and not close?

Answer 6

FRIENDS

F - foreign body
R - radiation
I - infection/inflammation
E - epithelialisation of fistula
N - neoplasia
D - distal obstruction
S - steroids

Question 7

What is meckel’s diverticulum?

Answer 7

Blind outpouching of antimesenteric aspect of the small intestine (ileum) - has all four layers of small bowel wall

True congenital diverticulum

Question 8

How does meckel’s occur

Answer 8

Incomplete obliteration of vitelline duct/ persistent remnant of the omphalomesenteric duct

Connects the midgut to the yolk sac in the foetus

If duct persists, meconium can be seen discharging from umbilicus

Question 9

Meckel’s can present with

Answer 9

Hematochezia/Melena (massive & painless, mostly in children)

Meckel’s diverticulitis - presents exactly like appendicitis

intestinal obstruction

Peptic ulceration - pain related to food, but felt around MIDGUT

Question 10

How to detect Meckel’s diverticulum on scans?

Answer 10

Technetium-99m pertechnetate

Detects gastric mucosa

**can also see ectopic thyroid tissue

Question 11

Crohn’s Disease vs Ulcerative Colitis

• Age
• Gender
• Clinical presentation

Answer 11

CD:
- 15-30, 50-60yo
- more females
- mucus-containing diarrhoea, pain, weight loss, fistula, IO

UC:
- 20-40, 60-80 yo
- more males
- bloody diarrhea, tenesmus, pain, fever

Question 12

Crohn’s Disease vs Ulcerative Colitis

• Extent of bowel involvement
• distribution
• Type of damage
• Risk of cancer

Answer 12

CD:
- anywhere from mouth to anus (esp ileum & ileocaecal junction, BUT spares rectum)
- Skip lesions
- Transmural damage (deep ulcers) with non-caseating granulomas, cobblestone appearance
- slight risk of CRC, increased risk of small bowel lymphoma

UC:
- large bowel (recto-sigmoid, left side mostly, ALWAYS affect rectum)
- Diffused, continuous lesions
- Shallow ulcers w pseudopolyps
- Greatly increased risk of CRC

Question 13

Systemic manifestations of inflammatory bowel disease

Answer 13

Joints: sacroilitis, ankylosing spondylitis
Eyes: conjunctivitis, episcleritis
Liver: primary sclerosing cholangitis (UC), fatty change
Kidney: ureteric calculi
Skin: erythema nodosum, pyoderma gangrenosum