GASTROENTEROLOGY (AB) Flashcards
Which esophageal sphincter controls entry into the esophagus?
Upper esophageal sphincter (UES)
What happens to UES pressure during deep sleep?
Decreases almost to zero
What happens to UES pressure during stress and straining?
Increases markedly
What are the two main functions of the UES?
Prevents air entry during respiration; Acts as a barrier to esophagogastric reflux
What is the primary function of the esophageal body?
Conducts peristaltic waves to propel food
What is the speed of esophageal peristalsis?
~3 cm/sec
What triggers primary peristalsis?
Swallowing
What triggers secondary peristalsis?
Gastroesophageal reflux (GER)
What is the normal resting pressure of the lower esophageal sphincter (LES)?
~20 mm Hg
What LES pressure is considered abnormal?
<10 mm Hg
What LES pressure maintains competence?
> 5 mm Hg
When does the LES relax?
Swallowing, belching, reflux events
What diagnostic test is best for structural anomalies like strictures and hiatal hernia?
Barium fluoroscopy
What esophageal abnormality is best evaluated with patient prone and barium via nasogastric tube?
H-type Tracheoesophageal Fistula
What does modified barium swallow assess?
Pharyngeal and esophageal phase coordination; detects aspiration and dysphagia
What diagnostic test directly visualizes mucosal abnormalities in the esophagus?
Esophagogastroduodenoscopy (EGD)
What conditions can EGD help differentiate?
GERD, eosinophilic esophagitis, infections (viral or fungal)
What diagnostic test evaluates peristalsis efficiency and detects reflux episodes?
Radionuclide scintigraphy
What is a radionuclide salivagram used for?
Demonstrates aspiration of small amounts of saliva
What test uses synchronized pressure measurements to assess esophageal dysmotility?
Esophageal manometry
What does high-resolution manometry (HRM) provide?
Detailed analysis of UES relaxation and peristaltic pressures
What diagnostic test measures acidity, duration, and frequency of reflux episodes?
Extended pH monitoring
What syndrome is associated with esophageal atresia and tracheoesophageal fistula?
VACTERL syndrome
What is the incidence of esophageal atresia and TEF?
1.7 per 10,000 live births
What is the most common type of esophageal atresia with TEF?
Type C (esophageal atresia with distal TEF)
What is the hallmark neonatal sign of esophageal atresia?
Inability to pass nasogastric/orogastric tube
What are two antenatal clues for esophageal atresia?
Absence of fetal stomach bubble; Maternal polyhydramnios
What radiographic finding suggests esophageal atresia?
Coiled feeding tube in esophageal pouch
What radiographic finding indicates a coexisting TEF?
Air-distended stomach
What is the most common primary esophageal dysmotility disorder?
Achalasia
What is the characteristic barium swallow finding in achalasia?
Bird’s beak sign
What is achalasia caused by?
Loss of LES relaxation and loss of esophageal peristalsis
What is a common infectious cause of achalasia?
Chagas disease (Trypanosoma cruzi)
What syndrome is associated with achalasia, alacrima, and adrenal insufficiency?
Triple A Syndrome (Allgrove Syndrome)
What condition mimics achalasia but is caused by malignancy or infiltration?
Pseudoachalasia
What clinical clues suggest pseudoachalasia?
Rapid onset, older age, weight loss
What is the first diagnostic test for suspected achalasia?
Endoscopy (to rule out malignancy)
What is the initial treatment of choice for achalasia?
Pneumatic dilation
What surgical procedure is performed for achalasia?
Laparoscopic Heller Myotomy
What minimally invasive procedure can be done for achalasia?
Peroral Endoscopic Myotomy (POEM)
What medication can temporarily relieve achalasia symptoms?
Calcium channel blockers (e.g., Nifedipine)
What endoscopic treatment temporarily relieves achalasia?
Botulinum toxin injection
What is the most common type of hiatal hernia?
Sliding hernia (Type 1)
What type of hiatal hernia involves the stomach fundus herniating next to the esophagus?
Paraesophageal hernia (Type 2)
What is the hallmark symptom of hiatal hernia?
Reflux
What is the key difference between gastroesophageal reflux (GER) and GERD?
GER is physiologic; GERD causes bothersome symptoms
What is Sandifer Syndrome?
Food refusal and neck contortions associated with GERD
When does physiologic GER typically resolve in infants?
By 12-24 months
What are common GERD symptoms in older children?
Abdominal/chest pain (heartburn), regurgitation
What symptom is more common in adolescents with GERD?
Heartburn
What is the most common foreign body ingested by children?
Coins
What radiographic sign helps distinguish esophageal from tracheal foreign bodies?
Flat surface seen on AP view for esophageal; Edge seen on lateral for tracheal
What is a key radiographic sign of disk battery ingestion?
Double rim sign
What type of injury does grade 2b caustic ingestion cause?
Discrete or circumferential ulceration with risk of perforation and later stenosis
What is the primary risk of grade 3b caustic ingestion?
High risk of perforation, death, and stenosis
What clinical signs suggest esophageal perforation after foreign body ingestion?
Cervical swelling, subcutaneous crepitus
What are key risk factors for esophageal atresia?
Advanced age, obesity, smoking
What is the survival rate for esophageal atresia and TEF?
> 90%
What respiratory symptoms suggest esophageal foreign body in children?
Stridor, wheezing, cyanosis, dyspnea
What common esophageal disorder is associated with eosinophilic esophagitis?
Food impactions
What is gastric duplication?
Uncommon cystic or tubular structures within the gastric wall
What is the prevalence of gastric duplication?
2–7% of all GI duplications
What is the common location for gastric duplication?
Greater curvature of the stomach
What is the typical size of gastric duplications?
Usually <12 cm in diameter
Do gastric duplications usually communicate with the gastric lumen?
No, but they share a common blood supply
What is gastric volvulus?
Abnormal rotation (twisting) of the stomach due to absence or elongation of ligamentous attachments
Which key ligaments are involved in gastric volvulus along the longitudinal axis?
Gastrohepatic, gastrosplenic, gastrocolic
Which key ligaments are involved in gastric volvulus along the transverse axis?
Gastrophrenic, retroperitoneal attachment of the duodenum
What is organoaxial volvulus?
Rotation along the longitudinal axis
What is mesenteroaxial volvulus?
Rotation along the transverse axis
What is combined gastric volvulus?
Rotation along both axes
What complication can result from gastric volvulus?
Twisting leads to necrosis
What is congenital duodenal obstruction?
Blockage of the duodenum present at birth
What is the incidence of congenital duodenal obstruction?
2.5–10 per 100,000 live births
What causes intrinsic duodenal obstruction?
Duodenal atresia due to failed recanalization during gestation
What imaging sign is associated with duodenal atresia?
Double-bubble sign
Which syndrome is commonly associated with duodenal atresia?
Down syndrome
What are examples of extrinsic causes of duodenal obstruction?
Annular pancreas, preduodenal portal vein, duplication cysts, congenital bands
What percentage of congenital heart disease is associated with duodenal atresia?
0.3
What percentage of annular pancreas is associated with duodenal atresia?
0.3
What complications can annular pancreas cause?
GERD, peptic ulcer disease, pancreatitis, recurrent obstruction
What percentage of duodenal atresia is associated with malrotation?
20-30%
What are symptoms of duodenal atresia at birth?
Bilious vomiting, abdominal distension
What is the key antenatal sign of duodenal atresia?
Polyhydramnios
What is the hallmark imaging finding for duodenal atresia?
Double-bubble sign with no distal gas
What is malrotation?
Incomplete or absent rotation of the intestine around the SMA during fetal development
What happens in the 5th week of gestation during normal intestinal development?
Mid bowel elongates and protrudes into the umbilical cord
What happens in the 12th week of gestation during normal intestinal development?
Rotation and fixation complete
Where should the duodenum move during normal rotation?
To the ligament of Treitz
Where should the cecum rotate during normal rotation?
To the right lower quadrant
What is nonrotation in malrotation?
Jejunum and ileum on the right, colon on the left
What is incomplete rotation in malrotation?
Cecum fails to move to the right lower quadrant
What is the significance of a narrow mesenteric base in malrotation?
Increased risk of midgut volvulus
What are Ladd bands?
Fibrous bands from cecum to RUQ, crossing and obstructing the duodenum
What is the major complication of malrotation?
Midgut volvulus
What is the hallmark symptom of midgut volvulus in infants?
Bilious vomiting
What severe symptoms can occur in malrotation with volvulus?
Shock, peritonitis
What are chronic symptoms of malrotation in older children?
Intermittent vomiting, abdominal pain, failure to thrive
What imaging finding on plain X-ray suggests duodenal obstruction?
Double-bubble sign
What is the gold standard imaging test for malrotation?
Upper GI series
What does a corkscrew appearance on upper GI series indicate?
Midgut volvulus
What is the whirlpool sign on ultrasound?
Twisting of mesenteric vessels
What is Meckel’s diverticulum?
Incomplete obliteration of the omphalomesenteric duct
What is the prevalence of Meckel’s diverticulum?
2-3%
Where is Meckel’s diverticulum located?
50-75 cm from the ileocecal valve on the antimesenteric border
What is the typical size of Meckel’s diverticulum?
3-6 cm
What types of ectopic tissue can be found in Meckel’s diverticulum?
Gastric and pancreatic
What is the Rule of 2s for Meckel’s diverticulum?
2% prevalence, 2 feet from ileocecal valve, 2 inches long, 2 types of ectopic tissue, 2:1 male predominance
What is the most common symptom of Meckel’s diverticulum?
Painless rectal bleeding
What complications can occur with Meckel’s diverticulum?
Intestinal obstruction, diverticulitis
At what age do bleeding symptoms from Meckel’s diverticulum usually present?
<2 years
What imaging test detects ectopic gastric mucosa in Meckel’s diverticulum?
Meckel Scan (Technetium-99m Pertechnetate)
What is functional constipation?
Chronic constipation meeting Rome IV criteria without organic cause
What are Rome IV criteria for functional constipation in infants?
2 or fewer defecations per week, excessive stool retention, hard/painful bowel movements, large-diameter stools, large rectal fecal mass
What additional criteria apply for toilet-trained children with functional constipation?
At least 1 weekly episode of incontinence, large stools that clog toilet
What are the Rome IV criteria for functional constipation in children ≥4 years?
≤2 defecations/week, ≥1 fecal incontinence episode/week, retentive posturing, painful stools, large rectal mass, large diameter stools
What is nonretentive fecal incontinence?
Inappropriate defecation with no evidence of fecal retention
What is the first-line medication for rapid rectal disimpaction in infants?
Glycerin suppositories
What is the phosphate enema dose for infants <1 year?
60 mL
What is the phosphate enema dose for children >1 year?
6 mL/kg up to 135 mL
What is the dose for polyethylene glycol with electrolytes for slow disimpaction?
25 mL/kg/hour until clear fluid
What is the maintenance dose of polyethylene glycol 3350 (MiraLAX) for children >1 year?
0.7 g/kg/day (max 17.5 g/day)
What is the dose of milk of magnesia for maintenance in infants >1 month?
1-3 mL/kg/day
What is the dose of lactulose for maintenance in infants >1 month?
1-3 mL/kg/day
What is the Senna dose for children 1-5 years?
5 mL with breakfast, max 15 mL daily
What is the Senna dose for children 5-15 years?
2 tablets with breakfast, max 3 tablets daily
What is the recommended glycerin enema dose for children >10 years?
20-30 mL/day
What is the bisacodyl suppository dose for children >10 years?
10 mg daily
