2025 – PAGE 237 – GASTROENTEROLOGY
CAUSES OF VOMITING
GASTROESOPHAGEAL REFLUX DISEASE (GERD)
Compared to pyloric stenosis, patients with gastroesophageal reflux disease (GERD) have vomiting that seems effortless. If the child is healthy, no need to treat. It will likely resolve by 18 months of age. Always consider overfeeding as a possible etiology. If there is apnea, signs of esophagitis (posturing), or poor weight gain, start a workup and also treat. A GI pH probe may help diagnose. Biopsy is unlikely to be an option, but choose GERD if eosinophils are noted on biopsy. You may treat with an H2 blocker (cimetidine or nizatidine) or with a proton pump inhibitor (PPI), such as omeprazole.
PEARL: Metoclopramide and sitting upright during feeds have not been shown to decrease reflux.
PEARL: If the patient is growing well, avoid medications. Offer reassurance or try hypoallergenic breastmilk/formula prior to starting a medication in infants. If you are going to prescribe an acid suppressant, try it for 2 weeks (famotidine would be acceptable as an option). Due to concerns for side effects, discontinue the medication if there’s no improvement. Know that studies have not shown any significant improvement with acid suppression in infants.
PEARL: Ranitidine is no longer available in the US due to an FDA black box warning of possible human carcinogen effects (gastric and colorectal cancer).
PYLORIC STENOSIS
Pyloric stenosis results from a gastric outlet obstruction due to a thickening or elongation of the pylorus. Look for NON-bilious, projectile emesis in a HUNGRY child. Labs may reveal a hypochloremic hypOkalemic metabolic alkalosis and possibly an elevated indirect bilirubin. An upper GI series may show the “string sign” or “railroad track “or “double track” sign. The railroad track sign is due to two lines of contrast created by thick muscle, with a connection due to contrast in rugae. Diagnosis is made by ultrasound showing a pylorus that is > 14 mm long or > 4 mm thick.
- SIDE NOTE: Alkalosis is initially from vomiting out HCl. As the patient becomes dehydrated, there is a superimposed contraction alkalosis.
- PEARLS: This occurs in boys > girls. Even if the serum potassium level is normal, the total body potassium is still likely low. If the serum pH is normal or acidotic, it is NOT pyloric stenosis. Erythromycin and azithromycin are BOTH associated with an increased risk of developing pyloric stenosis, but the risk is HIGHER with erythromycin (especially during the first two weeks of life). Give azithromycin when the baby is less than 6 weeks old.
- IMAGE: (Railroad Track) www.pbrlinks.com/PYLORIC1
- IMAGE: (String Sign) www.pbrlinks.com/PYLORIC2
- MNEMONIC: 4yloric stenosis, 14 mm, and 4 Remembering the diagnostic criteria can be tough. Use “4yloric stenosis” to help you.
ANTRAL WEB
An antral web is a membrane in the antrum of the stomach that can cause gastric outlet obstruction. It is usually formed before birth. It can present as polyhydramnios in utero, or non-bilious emesis in an infant less than 6 months of age. Imaging with barium may reveal a filling defect in prepyloric region.
ESOPHAGEAL WEB
A congenital esophageal web results from the failure of the esophagus to re-canalize in utero and presents with feeding difficulties early in life (particularly when transitioning to solids). If an esophageal web develops from inflammation, or iron deficiency, the age of presentation varies. Esophageal webs will act to obstruct food boluses. Liquids, however, pass through more easily. An esophageal web can cause reflux-like symptoms, esophageal impaction, and chest pain. Treatment requires dilation of the esophageal web.
IMAGE: www.pbrlinks.com/ESOPHAGEALWEB1
IMAGE: www.pbrlinks.com/ESOPHAGEALWEB2
PEARL: The “jet phenomenon” refers to the thin area of barium seen when looking at a barium swallow. It starts at the initial point of constriction. When that area is tortuous (www.pbrlinks.com/ESOPHAGEALWEB3), it can resemble a TE fistula. When it’s linear it does not ( www.pbrlinks.com/ESOPHAGEALWEBPDF– page 1 – see it and move on!).