1.10 Ileus (differential diagnosis, treatment)

Question 1

What are the types of ileus?

Answer 1

• mechanical ileus
• paralytic/function ileus

Question 2

What is paralytic ileus?

Answer 2

• there is non-mechanical decrease or stoppage of the flow of intestinal contents
• gas diffusely through the intestine, including colon

Question 3

What is mechanical ileus?

Answer 3

• bowel obstruction
• mechanical blockage of intestinal contents by mass, adhesion, hernia or some other physical blockage
• no air in colon, distended small bowel loops

Question 4

Classification of mechanical obstruction by site

Answer 4

• large bowel obstruction (LBO): cecum, colon, rectum
• small bowel obstruction (SBO): duodenum, jejunum, ileum
• gastric outlet obstruction (GOO): pylori channel, duodenum

Question 5

What is the etiology of paralytic ileus?

Answer 5

• recent abdominal surgery
• intraabdominal inflammation: appendicitis, diverticulitis etc.
• toxic megacolon
• acute colonic pseudo-obstruction

Question 6

What is the etiology of mechanical ileus?

Answer 6

• SBO: adhesions, hernia, neoplasm
• LBO: colorectal cancer, volvulus (loop of intestine twists around itself)

Question 7

Clinical features of mechanical ileus

Answer 7

• colicky abdominal pain
• vomiting
• constipation
• distention

Question 8

Clinical features of paralytic ileus

Answer 8

• diffuse, continuous abdominal pain
• vomiting
• consitpation
• distention
• absent bowel sounds

Question 9

Diagnostic imaging of mechanical ileus

Answer 9

• dilated bowel loops proximal to obstruction
• collapsed bowel loops distal to obstruction
• no air within rectum
• cause of obstruction (ie. tumor)

Question 10

Diagnostic imaging of paralytic ileus

Answer 10

• no evidence of mechanical obstruction
• diffusely dilated small and large bowel loops (ie. uniform distribution of gas)
• air within rectum
• absent peristalsis

Question 11

Consequences of bowel obstruction

Answer 11

stasis of luminal contents and gas proximal to the obstruction leads to increased intraluminal pressure, resulting in:
- gaseous abdominal distention: sequestration of fluids leading to dehydration and hypovolemia
- vomiting leading to hypokalemia, metabolic alkalosis and hypovolemia