Food is mixed with acid in the stomach and is passed through a valve known as the pylorus into the duodenum, the start of the small intestine. Some children are born with a congenital thickness of this valve, which causes a narrowing (stenosis).

A child or infant will show a characteristic projectile vomit due to the stomach compressing harder in order to force food through the stenosis but, in fact, pushing food up past the much weaker oesophageal stomach valve. The vomit is generally fermented food. The infant will not be growing and will be persistently hungry, therefore

Food is unable to pass through the pyloric valve to the duodenum. This results in extreme discomfort and vomiting. whining. The child may only want very small feeds because discomfort occurs if the stomach is filled and a diagnosis of constipation may be falsely suggested because the child only passes small amounts infrequently.

On occasions a knot may be felt in the upper part of the abdomen below the sternum (chest bone).

Any failure to thrive or a persistently uncomfortable child must be reviewed by a doctor or paediatrician.

Pyloric stenosis requires an operative procedure and can occur at any stage of life. Pain and symptoms of obstruction, such as bloating and constipation, arise and if not fixed quickly can result in bowel ischaemia and gangrene.

RECOMMENDATIONS 1 • Any abdominal pain that is severe or persistent must be reviewed by a doctor.