Definition
A pyloric stenosis usually becomes noticeable between the second and the sixth week of life. Due to a thickening of the musculature of the so-called stomach gate, a flow obstruction of the food in the area of the stomach outlet occurs. Symptomatically, there is gushing vomiting directly after meals, accompanied by a lack of weight gain, a massive loss of fluid and a shift in blood salts. In Germany, between 1 and 3 children per 1000 births suffer from pyloric stenosis. The risk of the disease is increased in premature babies and significantly underweight children, and the risk for a boy is 4 times higher than for girls.
Causes
A pyloric stenosis is a thickening of the muscles of the pylorus, the so-called stomach gate, which regulates the passage of food into the small intestine at the exit of the stomach. For reasons as yet unexplained, cramps, so-called spasms, of the pyloric musculature occur again and again. After some time, these lead to an increase in the thickness of the muscle cells, so that only little or, in advanced cases, no more food pulp can pass from the stomach into the small intestine.
As a result, a gastric emptying disorder develops and the stomach contents accumulate and build up a great deal of pressure until the infant immediately vomits the food it has ingested. Various factors are considered to be the cause. On the one hand, a genetic predisposition is suspected, since in many cases there is a familial predisposition.
On the other hand, changes in the nervous system as well as changes in the structure of the smooth muscles are discussed. In addition, a lack of certain nerve endings can be regarded as a cause for a lack of relaxation ability of the musculature, which leads to a release of growth factors and thus to a further increase and thickening of the muscle fibers. In addition, infants with blood groups 0 or B are more frequently affected than infants with a different blood group.