Bowel Obstruction

Question 1

partial obstruction

Answer 1

fluid/air continue to pass

Question 2

Complete obstruction

Answer 2

cessation of passage of stool or flatus

Question 3

Causes of osbtruction

Answer 3

extrinsic/extra-luminal (external to bowel)
Intrinsic (w/i wall of bowel)
intraluminal (defect that prevents passage of GI contents)

Question 4

Pathophys behind bowel obstruction

Answer 4

Excessive dilatation can compromise vascular supply leading to poor perfusion which can result in complications of: ischemia –> necrosis –> perforation
(volume depletion due to fluid sequestration in edeamatous bowel)

Question 5

Most common obstruction

Answer 5

SBO (surgical emergency)

Question 6

Vascular supply to small bowel

Answer 6

Superior mesenteric artery (SMA)

Question 7

Etiology/Risk Factors

Answer 7

ADHESION (post abdominal/pelvic surgery)**

Hernia
Neoplasm
Intestinal inflammation/intra-abdominal abscess
strictures (inflammatory, radiation, ischemic, anastomotic)
FB ingestion
Intussuscption
Volvulus

Question 8

Hx for SBO

Answer 8

surgery - risk increases w/ time - after 10 years
Family hx of cancer/radiation
any hernias?
N/V/D/C, hematochezia
pain worse or better?

Question 9

Sx of SBO

Answer 9

Abdominal pain

• start periumbilical, intermittent “cramping”
• more focal and constant pain can indicate peritonitis (bad sign)

Bloating/distention
anorexia
N/V/C
\+/- fever/chills/hematochezia
Obstipation - inability to pass flatus or stool (bad sign)

Question 10

PE for SBO

Answer 10

+/- fever, tachy, hypotension, shock (red flag)

General: mild/mod distress, lying motionless (red flag: peritonitis)

Skin: +/- decreased turgor, dry mucous membranes

Abdomen:

• distention, scars, hernias
• high pitched “tinkling” BS (early) or hypoactive/absent (late)
• percussion: tympany
• palpation: diffuse or local pain, mass?
• PERIOTNEAL SIGNS: guarding, rigidity, rebound tenderness (red flag)
• DRE: gross/occult blood, fecal impaction or rectal mass?

Question 11

Dx for SBO

Answer 11

CBC
CMP
Amylase/Lipase
UA
Lactate/LDH (tissue destruction)
Plain abdominal films (supine and upright)
CT scan- identify location, severity, etiology, complications

Question 12

CBC/CMP in SBO

Answer 12

+/- H/H, leukocytosis, anemia

+/- Bun/Cr (dehydration) +/- lyte abnormalities

Question 13

X-ray in SBO

Answer 13

dilated bowel w/ air fluid levels
proximal bowel dilation w/ distal bowel collapse

CXR: free air = perforation (red flag)

Question 14

Types of x-ray for SBO

Answer 14

supine

upright

Question 15

CT in SBO

Answer 15

dilated proximal bowel and collapsed distal
Bowel wall thickening > 3mm
Submucosal edema

Question 16

More diagnostics if CT/x-ray contraindicated or need more assessment

Answer 16

Abdominal US
CT/MR enterography
UGI/SBFT

Question 17

Tx of SBO

Answer 17

Admit
Consult surgery/GI
Trial of non-operative:
- NPO
- IVF
- electrolyte monitoring/replacement
- bowel decompression w/ NG tube******
- anti-emetics, analgesic, abx
- +/- gastrografin - dx and therapeutic

Question 18

How long do you monitor for non-operative SBO management

Answer 18

2-5 days (decrease distention, passage of flatus/stool, decrease NG output)

Question 19

SBO indications for surgery

Answer 19

• complicated (ischemia, necrosis, perforation)
• intestinal strangulation
• worsening sx or unresolved sx w/ NG tube and bowel rest

Question 20

Signs of complicated bowel obstruction

Answer 20

worsening abdominal pain
fever
tachycardia
leukocytosis
metabolic acidosis
peritonitis

Question 21

Signs of peritonitis

Answer 21

look sick
lie still
hypoactive/absent BS
peritoneal signs
significantly TTP

Question 22

Causes of strangulation

Answer 22

hernia
volvulus
intussusception (rare in adults; associated w/ tumor)

Question 23

What is ileus?

Answer 23

Hypomotility of GI tract in absence of mechanical bowel obstruction; often secondary to postoperative abdominal surgery (> w/ open and lower GI surgery)

inflammatory response

Question 24

Types of postop ileus

Answer 24

physiologic (benign, self-limited coarse)

Pathologic (no return of bowel function 4-6 days post op)

Question 25

Causes of ileus

Answer 25

``` postop (most common) hypomotility agents (opiods, antispasmodics, anticholinergics) ```

Question 26

Sx of ileus

Answer 26

``` abdominal pain distention/bloating "gassiness" N/V Inability to tolerate PO ```

Question 27

PE for ileus

Answer 27

distention & tympany variable reduction in BS mild tenderness

Question 28

Dx of ileus

Answer 28

Supine/upright x-ray: dilated bowel BUT air present in both small bowel and colon; no air fluid levels If needed, then CT

Question 29

Management of ileus

Answer 29

``` Supportive IVF Lyte replacement Pain mgt (avoid narcotics, use NSAIDS) bowel rest (NPO/CL diet +/- nutrition support) NG tube if persistent N/V Serial abdominal exams ambulate ```

Question 30

Vascular supply to large bowel

Answer 30

SMA | IMA

Question 31

Role of large bowel

Answer 31

absorb water and electrolytes (right colon); store feces (left colon)

Question 32

Etiology of LBO

Answer 32

ADENOCARCINOMA** (colon and rectal CA) ``` stricture: diverticulitis/ischemia Volulvus (sigmoid & cecal) IBD Fecal impaction FB ```

Question 33

Hx questions for LBO

Answer 33

``` hematochezia, bleeding, change in stool fam hx of CA LLQ pain w/ diarrhea (diverticulitis) Blood stool w/ diarrhea Time Chronic opiod use or chronic constipation ```

Question 34

Presentation of LBO

Answer 34

* +/- fever/chills * Crampy abdominal pain * Bloating, distention * Constipation/Obstipation * +/- N/V * Normal to quiet bowel sounds * Abdominal tenderness * +/- peritoneal signs * Hematochezia * DRE- occult blood, impaction, rectal mass?

Question 35

Dx of LBO

Answer 35

* CBC, CMP, UA, LDH/Lactate * Plain Abdominal Films – Supine and Upright * CXR to look for free air under diaphragm * Gastrograffin Enema (if x-ray unclear) * CT scan

Question 36

X-ray result for LBO

Answer 36

distended colon proximal to obstruction

Question 37

Tx of partial LBO

Answer 37

``` Trial of conservative: • Surgical Consult • NPO • IV Fluids • Antibiotics • Decompression with NG tube if vomiting • Avoid narcotics and anticholinergics ```

Question 38

Tx of complete LBO

Answer 38

``` Depends on cause: • Cancer – surgical resection • Complete stricture – surgical resection • Volvulus - Cecal: surgical resection (if > 12 cm) - Sigmoid: sigmoidoscopy with reduction • Intussusception – barium enema • Fecal impaction – enema ```

Question 39

What is volvulus

Answer 39

Abnormal twisting of a portion of the GI tract, usually the intestine, which can impair blood flow

Question 40

Types of volvulus

Answer 40

Sigmoid (most common) | Cecal

Question 41

Sigmoid volvulus risk factors

Answer 41

``` elderly (~70YO) Chronic constipation redundant sigmoid colon colonic dysmotility hypomotility agents ```

Question 42

Presentation of sigmoid volvulus

Answer 42

``` cramping ab pain N/V pain before vomiting constipation distended tympanitic abdomen TTP ```

Question 43

Dx of sigmoid volvulus

Answer 43

upright x-ray CT contrast enema - dx and therapeutic

Question 44

Tx of sigmoid volvulus

Answer 44

Flex sig: decompress and de-rotate | Surgery: resect redundant sigmoid colon and prevent recurrence

Question 45

Cecal volvulus risk factor

Answer 45

33-53 years

Question 46

Presentation of cecal volvulus

Answer 46

episodic pain to acute abdominal catastrophe distended typmanic

Question 47

Dx of cecal volvulus

Answer 47

upright x-ray - dilated cecum typically displaced medially superiorly CT scan- usually diagnostic

Question 48

Tx of cecal volvulus

Answer 48

Surgical