Small / Large Bowel Obstruction

Question 1

What is a bowel obstruction?

Answer 1

Mechanical blockage of the bowel

Question 2

What are the causes of SBO? (2 things)

Answer 2

1. Adhesions
2. Hernias

Question 3

What are the causes of LBO? (3 things)

Answer 3

1. Malignancy
2. Diverticular disease
3. Volvulus (bowel twisting on itself)

Question 4

What are the clinical features of BO? (3 + 2 things)

Answer 4

1. Vomiting
2. Abd pain / distension
3. Constipation

@ exam

4. Tympanic (hollow) sound on percussion
5. Tinkling bowel sounds on ausc

Question 5

What are the features of abd pain in BO? (3 things)

Answer 5

1. Colicky & cramping
2. Localised tenderness
3. Guarding + rebound @ palpation

Question 6

What does HIGHER up abd pain suggest in suspected BO?

Answer 6

SBO

Question 7

What does LOWER down abd pain suggest in suspected BO?

Answer 7

LBO

Lower pain = Large bowel

Question 8

What does EARLY vomiting suggest in suspected BO?

Answer 8

Proximal obstruction (SBO)

Remember: vomiting is from da mouth so da nearer obstruction is to da mouth da earlier it will present

Question 9

What does LATE vomiting suggest in suspected BO?

Answer 9

Distal obstruction (LBO)

Remember: vomiting is from da mouth so da nearer obstruction is to da mouth da earlier it will present

Question 10

What causes the abd pain in BO?

Answer 10

Peristalsis

Question 11

Which BO has MORE significant abd distension?

Answer 11

LBO

Question 12

What causes abdominal distension in BO?

Answer 12

Third spacing

Question 13

What is third spacing?

Answer 13

Movement of fluid from blood –> spaces between cells

Question 14

What does EARLY constipation suggest in suspected BO?

Answer 14

Distal obstruction (LBO)

Remember: pooing is from da bunda so da nearer da obstruction is to da bunda da earlier it willl present

Question 15

What does LATE constipation suggest in suspected BO?

Answer 15

Proximal obstruction (SBO)

Remember: pooing is from da bunda so da nearer da obstruction is to da bunda da earlier it willl present

Question 16

What are the types of BO? (3 things)

Answer 16

1. Simple
2. Closed loop
3. Strangulated

Question 17

What is simple BO? (2 things)

Answer 17

1. 1 obstruction point
2. NO vasc compromise

Question 18

What is closed loop BO?

Answer 18

2 obstruction points –> u get a loop of distended bowel –> risk of perforation

Question 19

What is a strangulated BO? (4 things)

Answer 19

1. Vasc compromise
2. Pain = sharper + constant + more localised
3. Peritonism signs
4. Mesenteric ischaemia signs

Question 20

What are the signs of mesenteric ischaemia? (3 things)

Answer 20

1. Fever (+ high WBC)
2. Pain worse @ movement
3. Localised tenderness

If dey have dese signs in BO den send dem for URGENT surgery cah is strangulated

Question 21

What are some other differentials that present similarly to BO?

Answer 21

1. Pseudo-obstruction
2. Paralytic ileus
3. Constipation

Question 22

What is a pseudo-obstruction?

Answer 22

Resembles mech GI obstruction but NO real obstructing lesion

Question 23

What is the treatment for pseudo-obstruction? (2 things)

Answer 23

1. Neostigmine (myasthenia gravis treatment)
2. Colonoscopic decompression

Question 24

What is paralytic ileus?

Answer 24

Impaired peristalsis of bowel

Question 25

What causes paralytic ileus? (3 things)

Answer 25

1. Abd / spinal surgery 2. Pancreatitis 3. Elec imb. (low Na / K)

Question 26

How do you differentiate between pseudo-obstruction / paralytic ileus VS BO? (2 things)

Answer 26

Pseudo-obstruction / paralytic ileus = 1. ABSENT bowel sounds 2. LESS pain

Question 27

What lab tests should be done for suspected BO? (5 things)

Answer 27

1. FBC 2. VBG 3. U&E 3. LFT 4. CRP 5. G&S

Question 28

What may a FBC show in suspected BO? (4 things)

Answer 28

1. High Hb = cancer 2. Low Hb = dehydration 3. Leucocytosis (inf / inflamm) 4. Anaemia = cancer

Question 29

What may a VBG show in suspected BO?

Answer 29

High lactate = ischaemia

Question 30

What may U&Es show in suspected BO? (2 things)

Answer 30

1. Elec imb (low Na / K) 2. Met alk (vomiting)

Question 31

Why should you do LFT's in suspected BO?

Answer 31

To exclude biliary / hepatic pathologies

Question 32

Why should you do G&S for suspected BO?

Answer 32

They might need surgery

Question 33

What is the gold standard imaging for suspected BO?

Answer 33

Abd / pelvis CT w IV contrast

Question 34

Why is CT \> AXR for suspected BO? (4 things)

Answer 34

1. More sensitive for BO 2. Can differentiate between mech obst vs pseudo-obst 3. Shows SITE + CAUSE of obst 4. Shows any METASTASES 3+4 = useful for operative planning

Question 35

What would a AXR show in SBO? (3 things)

Answer 35

1. Changes in CENTRAL abdomen 2. Dilated bowel (3+ cm) 3. Valvulae conniventes (lines COMPLETELY crossing bowel)

Question 36

What would a AXR show in LBO? (3 things)

Answer 36

1. Changes in PERIPHERAL abdomen 2. Dilated bowel (6+ cm / 9+ cm @ caecum) 3. Haustra (lines that only cross bowel Halfway)

Question 37

If clinical features suggest bowel perforation in BO what scan should you do and why?

Answer 37

Erect XR To check for air under diaphragm

Question 38

What determines the management methods for BO?

Answer 38

Cause / site / obst completeness / complications

Question 39

What are the indications for surgery in BO? (4 things)

Answer 39

1. Closed loop / strangulated BO 2. Ischaemia signs 3. LBO 4. Conservative not helping for 48+ hours

Question 40

What is the conservative management for BO called?

Answer 40

Drip & Suck

Question 41

What is the conservative management for BO? (6 things)

Answer 41

1. DRIP: IV fluids (rehydrate + correct elec imb) 2. SUCK: NG Tube (decompress bowel prox to obst) 3. NBM 4. Analgesia 5. Anti-emetics 6. Urinary catheter

Question 42

What is the surgical management for BO? (2 things)

Answer 42

1. Laparatomy 2. Bowel resection + stoma insertion