E2: Bowel Obstruction

Question 1

What is a bowel obstruction?

Answer 1

-Blockage of the bowel that occurs when the normal flow of intraluminal contents is interrupted

Question 2

What is the difference between a partial and complete bowel obstruction?

Answer 2

• partial: fluid and air continue to pass

- complete: cessation of passage of stools and gas

Question 3

What are the 3 major causes of bowel obstruction?

Answer 3

• extrinsic/extra-luminal (external to bowel, such as adhesions and intra-abdominal abscess)
• Intrinsic (within the wall of the bowel, such as neoplasm and stricture)
• Intraluminal (fecal impaction, FB)

Question 4

What is the pathophysiology of a bowel obstruction?

Answer 4

-Obstruction leads to bowel dilation and retention of fluid within the lumen proximal to obstruction, while distal to the obstruction, the bowel decompresses

Question 5

What are the main complications of bowel obstruction?

Answer 5

Ischemia -> necrosis -> perforation

Question 6

What kind of obstruction accounts for 80% of obstructions?

Answer 6

SBO

Question 7

What is the most common cause of SBO?

Answer 7

Adhesions

Question 8

Patient presents with abdominal pain and constipation. On PE, you hear high pitched “tinkling” bowel sounds. What are you concerned about?

Answer 8

SBO

Question 9

What will you see on supine and upright abdominal XRs if the patient has an SBO?

Answer 9

• Dilated loops of bowel with air fluid levels

- proximal bowel dilation with distal bowel collapse

Question 10

What will you see on CT if the patient has an SBO?

Answer 10

• Dilated proximal bowel with distal collapsed loops
• bowel wall thickening >3mm
• submucosal edema

Question 11

What are the indications for surgical exploration for an SBO?

Answer 11

• Complicated bowel obstruction as evidenced by worsening pain, fever, tachycardia, leukocytosis, metabolic acidosis, and peritonitis
• intestinal strangulation
• worsening symptoms

Question 12

What is the non-operative management of SBO?

Answer 12

• NPO
• volume resuscitation
• electrolyte monitoring and replacement
• bowel decompression with NG tube
• Anti-emetics
• Gastrograffin (diagnostic and therapeutic)

Question 13

What is an ileus?

Answer 13

Hypomotility of the GI tract in the absence of a mechanical bowel obstruction, often secondary to postoperative abdominal surgery

Question 14

What will you see on abdominal XR if the patient has an ileus?

Answer 14

Dilated loops of bowel but air is present in both small and large bowel. No air fluid levels

Question 15

What is the management of an ileus?

Answer 15

-Supportive care with IV fluids, lyte replacement, pain management, bowel rest, bowel decompression with NG tube if persistent N/V

Question 16

What is the most common etiology of a large bowel obstruction?

Answer 16

Adenocarcinoma

Question 17

What will you see on supine and upright abdominal Xr if patient has an LBO?

Answer 17

Distended colon proximal to the obstruction

Question 18

What is the management of a partial LBO?

Answer 18

• Surgical consult
• NPO
• IV fluids
• ABX
• decompression with NG tube
• Avoid narcotics and anticholinergics

Question 19

What is the management of a complete LBO?

Answer 19

• Cancer: surgical resection
• complete stricture: surgical resection
• intussusception: Pneumatic reduction
• Fecal impaction: enema

Question 20

What is a volvulus?

Answer 20

• Abnormal twisting of a portion of the GI tract, usually the intestine which can impair blood flow
• can be sigmoid (most common) or cecal

Question 21

What is the management of a sigmoid volvulus?

Answer 21

-Flex sig to decompress and de-rotate, surgery to respect redundant sigmoid colon and prevent recurrence