BOWEL INSTRUCTION

Question 1

Pertinent Anatomy of a patient with Bowel Obstruction.

Answer 1

(1) Small intestine

(2) Large intestine

Question 2

This type of obstruction can be caused by either intrinsic or extrinsic factors and generally requires definitive intervention in a relatively short period of
time to determine the cause and minimize subsequent morbidity and
mortality.

Answer 2

Mechanical

Question 3

Common causes of Intestinal Obstruction

Duodenum

Answer 3

1) stenosis,
2) foreign body (Bezoars),
3) stricture,
4) superior mesenteric artery syndrome

Question 4

Common causes of Intestinal Obstruction

Small bowel

Answer 4

1) adhesions,
2) hernia,
3) intussusception,
4) lymphoma,
5) stricture

Question 5

Common causes of Intestinal Obstruction

Colon

Answer 5

1) carcinoma,
2) fecal impaction,
3) ulcerative colitis,
4) volvulus,
5) diverticulitis (stricture, abscess),
6) intussusception,
7) pseudo-obstruction

Question 6

The most common cause of Small Bowel Obstruction (SBO)

Answer 6

adhesions following abdominal surgery.

Question 7

The second most common cause of Small Bowel Obstruction (SBO)

Answer 7

incarceration of a groin hernia.

Question 8

Other sites that occasionally are responsible for SBO secondary to hernia
include

Answer 8

umbilicus, femoral canal, and rarely, the obturator foramen.

Question 9

Primary small bowel lesions include

Answer 9

polyps, lymphoma, or adenocarcinoma.

Question 10

most common cause of LBO.

Answer 10

Neoplasms

Question 11

what may create significant secondary obstruction. (LBO)

Answer 11

Diverticulitis

Question 12

what may occur with chronic inflammation and scarring.

Answer 12

Stricture formation

Question 13

Fecal impaction is a common problem in what population.

These people may present with symptoms of colonic obstruction.

Answer 13

elderly

debilitated patients

Question 14

Symptoms

Answer 14

(1) crampy and intermittent abdominal pain.
(a) SBO- often episodic, usually lasting for a few minutes at a time, and it may be periumbilical or more diffuse.
(b) LBO- usually hypogastric.
(c) Adynamic ileus-pain is less intense and more constant.
(2) If the obstruction is proximal-vomiting; usually bilious but is feculent in distal small bowel obstruction or large bowel obstructions.
(3) inability to have a bowel movement or pass flatus (SBO and LBO)

Question 15

Differential Diagnosis

Answer 15

(1) Constipation

(2) Inflammatory Bowel Syndrome

Question 16

Lab

Answer 16

(1) Laboratory studies usually include a complete blood count and electrolyte levels.
(a) A white count greater than 20,000/L or left shift should make one suspect
bowel gangrene, intra- abdominal abscess, or peritonitis.

Question 17

RAD

Answer 17

(1) All patients with suspected obstruction should have flat and upright abdominal
radiographs and upright chest x-ray.
(a) An abdominal radiograph can confirm the diagnosis, identify free air or masses, and localize the site to large or small bowel

Question 18

Treatment

Answer 18

(1) If a true mechanical obstruction -surgical intervention is often required.
(a) A nasogastric tube should be inserted to remove excess bowel contents and air.
(b) IV fluid replacement is needed
(c) Patients with mechanical obstruction require broad-spectrum antibiotic coverage Ertapenem (Invanz) 1g IV Q 24 hrs
(2) If adynamic ileus- conservative measures, including IV fluids, nasogastric decompression, and observation,
generally are effective in allowing the bowel to resume normal activity and function.
(a) Any medication that inhibits bowel mobility should be discontinued

Question 19

Initial Care

Answer 19

(1) Identify true obstruction, abrupt onset of abdominal distension is good indicator.
(2) Treatment symptomatically (assess vitals for proper stabilization treatment)

Question 20

Disposition

Answer 20

MEDEVAC

Question 21

the inability of the intestinal tract to allow for regular passage of food and bowel contents secondary to mechanical obstruction or adynamic ileus.

Answer 21

Intestinal obstruction

*(a) Adynamic ileus (paralytic ileus) is the more common entity but is usually
self- limiting and does not require surgical intervention.

Question 22

(4) Physical exam presentation

Answer 22

(a) Early symptoms-abdominal distention, often impressive.
(b) The abdomen may be tympanic to percussion.
(c) Mechanical obstruction will produce active, high- pitched bowel sounds with
occasional “rushes.”
(d) Adynamic ileus may have diminished or absent bowel sounds.
(e) All patients with abdominal pain or distention should be examined for signs
of organomegaly or masses that may suggest a cause of the obstruction.