Gastroenterology

Question 0

Intussusception triad

Answer 0

Abdominal pain
Vomiting
Currant jelly (bloody) stool

Question 1

Intussusception definition

Answer 1

Bowel that telescopes into an adjacent segment, usually proximal to ileocecal valve

Question 2

History and PE of intussusception

Answer 2

Abrupt-onset, colicky abdominal pain in healthy children
Accompanied by flexed knees and vomiting
Sausage shaped RUQ abdominal mass

Question 3

Dx of intussusception

Answer 3

Abdominal plain films are usually normal early in dz

U/S is the test of choice: shows a TARGET SIGN

Question 4

Tx of intussusception

Answer 4

NG tube for decompression
Air-contrast barium enema is diagnostic and curative in most cases
Unstable/peritoneal signs/refractory: perform surgical reduction and resection of gangrenous bowel

Question 5

Pyloric stenosis associations

Answer 5

Tracheoesophageal fistula
Maternal hx of pyloric stenosis
Erythromycin ingestion

Question 6

PE of pyloric stenosis and when does it start?

Answer 6

Pyloric stenosis causes gastric outlet obstruction: NON-BILIOUS PROJECTILE VOMITING
Begins at 3 weeks of age

Question 7

Metabolic derangement in pyloric stenosis

Answer 7

Hypochloremic hypokalemic metabolic alkalosis

-all through loss of HCl and K in vomiting

Question 8

Meckel’s diverticulum cause

Answer 8

Failure of omphalomesenteric duct to obliterate (aka vitelline duct)
The resulting hetertopic gastric tissue causes ulcers and bleeding

Question 9

Meckel’s rule of 2s

Answer 9

Children < 2y/o
2x more common in males
2 types of tissue: pancreatic and gastric
2 inches long
Found within 2 feet of the ileocecal valve
Occurs in 2% of population

Question 10

Classical presentation of Meckel’s diverticulum

Answer 10

Sudden, intermittent, painless rectal bleeding

Question 11

Complications of Meckels

Answer 11

Intestinal obstruction
Diverticulitis
Volvulus
Intussusception

Question 12

Dx of Meckel’s diverticulum

Answer 12

Meckel scintigraphy scan with technetium-99m pertechnetate

-it detects ectopic gastric tissue

Question 13

Hirschsprung disease associations

Answer 13

Down syndrome, male gender, MEN II, Waardenburg’s syndrome

Question 14

Common presentation of Hirschsprung disease: timeline

Answer 14

Neonates p/w failure to pass meconium within 48 hours of birth
-but it can occur in older children
Bilious vomiting
Failure to thrive
Explosive discharge of stool following rectal exam

Question 15

Dx of Hirschsprung disease

Answer 15

Barium enema reveals a narrow distal colon w/ proximal dilation
Plain films will show distended bowel loops with a paucity of air in the rectum
Anorectal manometry detects failure of the internal sphincter to relax after distention of the rectal lumen
Rectal biopsy: absence of myenteric plexus (aka Auerbach’s) and submucosal plexus (aka Meissners) along with hypertrophies nerve trunks enhanced w/ AChesterase stain

Question 16

Tx of Hirschsprung disease

Answer 16

2 stage surgical repair:

• creation of a diverting colostomy at the time of diagnosis
• definitive pull through procedure connecting the remaining colon to the rectum a few weeks later

Question 17

Malrotation with volvulus pathophysiology

Answer 17

Congenital malrotation of the midgut -> abnormal positioning of the small intestine with the cecum in the right hypochondrium
It also forms Ladd’s bands (fibrous bands) which predispose to obstruction and constriction of blood flow

Question 18

Common presentation of malrotation with volvulus including timeline

Answer 18

Often presents in first month of life with bilious emesis, crampy abdominal pain, distention, and passage of blood/mucus in stool

Question 19

Diagnosis of malrotation with volvulus

Answer 19

Abdominal X-ray: bird-beak appearance and air-fluid levels; but it could appear normal
Upper GI (barium + X-ray) is STUDY OF CHOICE if patient is stable
-shows abnormal location of the ligament of Treitz

Question 20

Tx of malrotation

Answer 20

NG tube insertion to decompress
IVF hydration
If the volvulus is gastric, then emergent surgical repair is required; if it’s intestinal, then surgery or endoscopy could work

Question 21

Necrotizing enterocolitis definition

Answer 21

A condition in which a portion of the bowel undergoes necrosis
Most common GI emergency in neonates
Seen in premature infants

Question 22

Presentation and time course of necrotizing enterocolitis

Answer 22

Usually presents within the first few days or weeks of life
Non specific sx: feeding intolerance. delayed gastric emptying, abdominal distention, and bloody stools
Sx may rapidly progress to intestinal perforation, peritonitis, abdominal erythema, shock

Question 23

Dx of necrotizing enterocolitis

Answer 23

Pathognomonic: pneumatosis intestinalis on plain films
-these are intramural air bubbles representing gas produced by bacteria within the bowel wall

Can also show portal venous gas, abdominal free air

Question 24

Tx for necrotizing enterocolitis

Answer 24

NPO + NG tube + IVF + TPN + IV antibiotics Surgery if: perforation, worsening radiographic signs -ileostomy with mucous fistula followed by a reanastomosis

Question 25

Complications of necrotizing enterocolitis

Answer 25

Intestinal strictures and short-bowel syndrome

Question 26

Differential for conjugated hyperbilirubinemia

Answer 26

Extrahepatic cholestasis (ie biliary artresia, choledochal cysts) Inhtrahepatic cholestasis (ie noeonatal hepatitis, inborn errors of metabolism, TPN, cholestasis) Dubin-Johnson Rotor's syndrome TORCH infections

Question 27

Ddx for unconjugated hyperbilirubinemia

Answer 27

``` Physiologic jaundice Hemolysis Breast milk jaundice Increased enterohepatic circulation ie GI obstruction Disorders of bilirubin metabolism hemolysis Gilbert's syndrome Criggler-Najjar sepsis ```