Lower GI

Question 1

5 F’s of abdominal distension

Answer 1

Fat
Fluid: ? Ascites
Flatus: ? Obstruction
Foetus: ? Pregnancy
Faeces: ? Obstruction/ Impaction

Question 2

Most common cause of small bowel obstruction?

Answer 2

Adhesions

Question 3

Most common cause of large bowel obstruction?

Answer 3

Malignancy

Question 4

How does bowel obstruction usually present?

Answer 4

Constipation
N+V
Abdominal distension

Question 5

Give 3 characteristics of anatomical obstruction

Answer 5

Colicky
Distension
Intermittent diarrhoea (overflow)

Question 6

List 5 causes of anatomical obstruction

Answer 6

Diverticular disease
Colonic carcinoma
Extrinsic compression: pregnancy, ovarian tumour
Hernia
Volvulus

Question 7

List 4 causes of functional obstruction

Answer 7

Paralytic ileus: elderly, electrolyte deficiency
Spinal cord injury (CES)
Toxic megacolon
Post-op ileus

Question 8

Name a congenital cause of bowel obstruction

Answer 8

Hirschsprungs disease

Question 9

Investigations for suspected bowel obstruction

Answer 9

Bedside: full abdo exam +/- DRE
Bloods: FBC, U+Es, LFT, CRP, 2x G+S, clotting screen
Imaging: erect CXR, AXR, CT AP

Question 10

Why perform a CXR in suspected bowel obstruction?

Answer 10

To look for pneumoperitoneum indicative of perforation

Question 11

What are the diameters at which bowel is considered distended?

Answer 11

Small bowel: 3cm
Large bowel: 6cm
Caecum: 9cm

Question 12

Where is the obstruction? Where is it most likely to perforate?

Answer 12

Large bowel
Most likely to perforate at caecum (most common site in all LBO)

Question 13

Describe a closed loop obstruction

Answer 13

Mechanical obstruction distally, competent ilea-caecal valve proximally
Surgical emergency: if not corrected, bowel will continue to distend within a closed segment of bowel, stretching the wall until it becomes ischaemic + can lead to perforation.

Question 14

Appearance of small vs large bowel obstruction on imaging

Answer 14

Small: Central. Valvular conniventes (traverse bowel wall)
Large: Peripheral, circumferential “frames” small bowel. Haust, dont completely cross bowel wall “Haustra go Halfway”

Question 15

Management for bowel obstruction

Answer 15

NBM
Analgesia
Antiemetic
Ryles NG tube
IV fluids

Surgical: dependent on identified cause of obstruction (CT AP)

Question 16

Name Scar A

Answer 16

Midline incision

Question 17

Name Scar B

Answer 17

Paramedian

Question 18

Name Scar C

Answer 18

Kocher’s scar

Question 19

Name Scar D

Answer 19

Roof top scar (Chevron)

Question 20

Name Scar E

Answer 20

Lateral

Question 21

Name Scar F

Answer 21

Gridiron

Question 22

Name Scar G

Answer 22

Lanz

Question 23

Name Scar H

Answer 23

Suprapubic (Pfannenstiel)