Pyloric stenosis is a narrowing of the pylorus, the lower part of the stomach through which food and other stomach contents pass to enter the small intestine. Pyloric stenosis is fairly common - it affects about three out of 1,000 babies. Most infants who develop pyloric stenosis are usually between 2 weeks and 2 months of age - symptoms usually appear during or after the third week of life. It is believed that babies who develop the condition are not born with pyloric stenosis, but that the progressive thickening of the pylorus occurs after birth. An affected infant begins showing symptoms when the pylorus is so thickened that the stomach can no longer empty properly. The first symptom of pyloric stenosis is usually vomiting. Projectile vomiting, in which the breast milk or formula is ejected forcefully from the mouth, in an arc, sometimes over a distance of several feet. Projectile vomiting usually takes place soon after the end of a feeding. The vomit will not contain bile. Babies with pyloric stenosis usually have fewer, smaller stools because little or no food is reaching the intestines. Most babies with pyloric stenosis will fail to gain weight or will lose weight. As the condition worsens, they are at risk for developing fluid and salt abnormalities and becoming dehydrated. After feeds, increased stomach contractions may make noticeable ripples, or visible peristalsis, which move from left to right over the infant's belly. During the exam, there is a pyloric mass - a firm, movable lump that feels like an olive on the right side of abdomen.
USG of abdomen is the diagnostic modality, but sometimes the barium studies of upper tract is done which shows narrowing at pylorus & Delayed passage of barium through thickened pyloric channel. The enlarged, thickened & elongated pylorus can be seen on ultrasound images.
A surgical procedure called pyloromyotomy, which involves cutting through the thickened muscles of the pylorus, is performed to relieve the obstruction from pyloric stenosis. The pylorus is examined through a very small incision, and the muscles that are overgrown and thickened are spread to relieve the obstruction.