GIT IV (SBO)

Question 1

Congenital causes

Answer 1

Jejunal atresia
Meckel diverticulum
Midgut volvulus
Enteric duplication
Mesenteric cyst
Meconium ileus

Question 2

Acquired causes of SBO

Answer 2

Extrinsic (complression):
Adhesion, hernia, mass
Intraluminal:
FB, galls stone ileus, bezoar, migration of gastric ballon.
Intrinsic:
Inflammation(crohn’s), TB, Tumor, Intussusception, ischemia, radiation

Question 3

Features on abdominal Radiograph:

Answer 3

• Central dilated loops
• Dilated loops of SB proximal to the obstruction > 3cm
Valvulae conniventes are visible
Gas-fluid levels if the study is erect.

Question 4

What is the rule of 3-6-9

Answer 4

Small bowel: < 3 cm
Large bowel TC: < 6 cm
Cecum: < 9 cm

Appendix: <6 mm

Question 5

High-grade mechanical obstruction may also present with the following features:

Answer 5

Gasless abdomen
String of pearls sign

Question 6

Signs of SBO secondary to adhesion:

Answer 6

• Dilated small bowel loops proximally
• Thickened mucosa (valvulae conniventes)
• Cut-off sign distally
• ++++ diameter of bowel
• don’t forget that the upper limit is 3 cm of diameter

Question 7

SBO on US:

Answer 7

• Dilated bowel loop (>3cm)
• Decrease of absent peristalsis
• Prominence valvulae conniventes

Question 8

US findings suggestive of bowel ischemia

Answer 8

• Extra luminal free fluid
• Loss of peristalsis
• Bowel wall thickening >3mm
• Mural gas

Question 9

Which sensitive for SBO radiograph or CT

Answer 9

CT, and will demonstrate the cause in ~80% of cases

Question 10

Meconium ileus onAXR

Answer 10

• Small bowel obstruction
• Dilated loops proximal to impaction
• Soap-bubbly pattern of impaction
• No Air-fluid level

Question 11

Meconium ileus on FL enema shows:

Answer 11

Small unused microcolon
Filling defects representing meconium pellets in the terminal ileum

Question 12

Is AXR good for intussusception?

Answer 12

No, it is not sensitive or specific

Question 13

Intussusception on AXR 🤷‍♂️

Answer 13

May be normal or:
• Soft tissue mass surrounded by a crescent of gas
• Evidence of distal small bowel obstruction
• Absence of or decreased gas in the colon
• Pneumoperitoneum may seen

Adults usually normal bowel gas pattern

Question 14

Gold standard diagnostic and therapeutic of intussusception

Answer 14

Barium enema

Question 15

What are two signs of intussusception on barium enema

Answer 15

• Meniscus sign
• Coiled spring appearance

Question 16

Signs of intussusception on US (for pediatric):

Answer 16

Transverse: Target or duoghnut sign
Oblique: pseudo kidney sign
Longitudinal: Sandwich, trident
Doppler may help determine viability of the tissue

Question 17

Intussusception on US (for adult)

Answer 17

Less useful
It is useful when an abdominal mass is palpated

Question 18

Intussusception on CT

Answer 18

Most commonly done for adult, and pathognomonic:
Axial: Target sign, with layers kf fat and bowel wall visible.
Coronal: Elongated, sausage-shaped mass with visible layers.