Pyloric Stenosis
Basics
Description
- Postnatal hypertrophy of the circular smooth muscle of the pylorus valve and antrum leading to progressive gastric outlet obstruction
- Usually presents at 2–6 wk of age; rarely after 12 wk
- Most common cause of GI obstruction in infants; incidence: 1–3.5/1000 live births
- Males affected 5× more than females; 1st born most common
Etiology
- Exact etiology unknown
- Familial aggregation noted:
- Child of affected parent has 7% incidence
- Recurrence risk in subsequent male children is 10%; 2% in females
- Use of erythromycin and azithromycin in infants during 1st 2 wk of life may increase risk
- Maternal smoking and formula feeding may also increase risk
- Adults: Caused by peptic ulcer disease
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Citation
Schaider, Jeffrey J., et al., editors. "Pyloric Stenosis." 5-Minute Emergency Consult, 7th ed., Wolters Kluwer, 2027. Emergency Central, emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307156/2.2/Pyloric_Stenosis.
Pyloric Stenosis. In: Schaider JJJ, Barkin RMR, Hayden SRS, et al, eds. 5-Minute Emergency Consult. Wolters Kluwer; 2027. https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307156/2.2/Pyloric_Stenosis. Accessed July 13, 2026.
Pyloric Stenosis. (2027). In Schaider, J. J., Barkin, R. M., Hayden, S. R., Wolfe, R. E., Barkin, A. Z., Shayne, P., & Rosen, P. (Eds.), 5-Minute Emergency Consult (7th ed.). Wolters Kluwer. https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307156/2.2/Pyloric_Stenosis
Pyloric Stenosis [Internet]. In: Schaider JJJ, Barkin RMR, Hayden SRS, et al, eds. 5-Minute Emergency Consult. Wolters Kluwer; 2027. [cited 2026 July 13]. Available from: https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307156/2.2/Pyloric_Stenosis.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Pyloric Stenosis
ID - 307156
ED - Barkin,Adam Z,
ED - Shayne,Philip,
ED - Rosen,Peter,
ED - Schaider,Jeffrey J,
ED - Barkin,Roger M,
ED - Hayden,Stephen R,
ED - Wolfe,Richard E,
BT - 5-Minute Emergency Consult
UR - https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307156/2.2/Pyloric_Stenosis
PB - Wolters Kluwer
ET - 7
DB - Emergency Central
DP - Unbound Medicine
ER -

5-Minute Emergency Consult

