The testicles are formed at the spot where the kidneys are situated, high up behind the abdominal cavity. From there they descend through the inguinal canal into the scrotum. On that journey — the baby boy is still in his mother’s womb — they take the front of the abdominal membrane with them. When things proceed normally this bulge in the abdominal membrane closes, so that there is no open connection left with the abdominal cavity. The remnant of abdominal membrane in the scrotum surrounds the testicles for the rest of the individual’s life as a doublelayered protective membrane.
If that hernial sac does not close around birth, then there is a chance that the intestine of the newborn infant will descend as far as the scrotum, creating a so-called innate hernia, which sometimes manifests itself as a sizeable swelling. Of course a hernia requires surgery — in boys with a scalpel, in adults mostly by means of keyhole surgery. Adults in whom the abdominal membrane has closed properly may suffer a hernia because of an increase in pressure due, for example, to chronic coughing or a great deal of heavy lifting. Often the intestines bulge into the groin but do not reach the scrotum. The doctor can ascertain whether there is a hernia by having the man blow against the back of his hand while standing and himself feeling the inguinal canal with his finger from the scrotum.