Diagnosis
Clinical symptoms provide the first decisive indications of the presence of pyloric stenosis. However, in order to diagnose pyloric stenosis with certainty, an ultrasound examination and a blood gas test are required. Blood gas analysis typically shows evidence of a significant loss of fluid, as well as a shift in blood salts in the form of a decrease in potassium (hypokalemia), a decrease in chloride and an increase in pH to the basic range (alkalosis).
If no clear diagnosis can be made sonographically, a missing or delayed passage of food can be reliably shown or even excluded by means of an X-ray contrast medium imaging of the upper stomach and intestinal tract. Sonography is the method of choice for the reliable diagnosis of pyloric stenosis in infants. By means of ultrasound, the stomach can in most cases be displayed clearly filled with fluid and with increased activity of the muscles in the right upper abdomen. In addition, a reduced or completely absent transport of stomach contents via the gatekeeper can be shown. As a safe criterion, an extended pyloric channel of more than 17 mm and a thickening of the musculature of more than 3 mm can be measured in ultrasound.
Associated symptoms
Pyloric stenosis can be accompanied by a variety of accompanying symptoms. Nevertheless, there are some symptoms that should be given special attention, as they make the presence of a pyloric stenosis very likely. A characteristic feature is the occurrence of vomiting, which sets in about 10 – 20 minutes after a meal.
The infant vomits in short successive time intervals in a torrential manner and a particularly large quantity. The vomit has an acidic smell and in some cases may contain small blood filaments due to irritation of the stomach lining and the mucous membranes of the upper digestive tract. There is also a noticeable weight loss.
When looking at the infant externally, sometimes the stomach gate can be seen or palpated as an olive-sized, roundish structure in the right upper abdomen. In addition, the increased movement of the stomach muscles is often visible as an undulating movement of the stomach skin. Due to the resulting loss of fluid, the skin of the affected infants appears dry and typical signs of dehydration such as a sunken fontanel, deep rings under the eyes or standing skin folds are visible.In addition, due to the lack of fluid, infants produce significantly less urine and are often very restless and drink particularly greedily. Through vomiting, the infants lose not only the liquid but also the acid gastric juice, which causes a shift of the PH value to the alkaline range (alkalosis).
