Kids Health Info

Inguinal hernia

  • A hernia is a lump or protrusion of an organ (usually the small bowel or fatty material) through a weakness or opening in the muscle wall of the abdomen. It is usually seen as a bulge under the skin.

    An inguinal hernia is a hernia that occurs in the groin region.  In boys, an inguinal hernia may extend into the scrotum. It affects 1%-5% of full-term babies. It is more common in boys (10%) and in premature babies (7%-30%). Boys are four to eight times more likely than girls to have an inguinal hernia.

    What causes it?

    In boys, the testes are initially located in the abdomen. Around the seventh month of gestation, the testes migrate down into the scrotum via a passage calledd the inguinal canal. This canal begins to close before birth and is normally completely fused or shut by the first year of life. If this canal does not close completely and the muscles in the wall of the abdomen do not cover the opening well enough, a hernia may develop.

    Though less likely, girls can also develop an inguinal hernia. They have a similar but smaller passage.

    Infants who are at higher risk include those who:

    • were born prematurely or with low birth weight;
    • have someone else in the immediate family who had an inguinal hernia as a baby;
    • have other urological problems (e.g. undescended testes).

    There is nothing you did or did not do that caused the hernia to develop. The opening in the abdominal wall is present from birth and a hernia may develop at any time. It is usually picked up in newborns or within the first year of life. However, it may go unnoticed for many years. There is no routine treatment of newborns that will prevent the development of a hernia.

    Hernias are slightly more common on the right side, but can occur on the left or on both sides.

    Hernias are more noticeable during, but they are NOT caused by:

    • crying; or
    • straining.


    Symptoms may include:

    • A swelling or visible lump in groin.
    • A swelling in the scrotum.

    The swelling:

    • is usually painless (but may have some mild discomfort);
    • is soft and smooth in texture;
    • may disappear or reduce in size when baby is relaxed and lying flat;
    • may appear or increase in size when baby is crying, coughing or straining.

    Reducible and irreducible hernia

    In a simple hernia, the bowel and fatty tissue are able to move freely in and out of the defect.  This is described as being reducible. If part of the bowel becomes trapped and cannot return to the abdomen, it is at risk of having its blood supply cut off. This is then irreducible and is described as an incarcerated hernia.

    Symptoms of an incarcerated inguinal hernia

    The symptoms of an incarcerated inguinal hernia can include:

    • child appearing ill;
    • pain in the groin;
    • nausea and vomiting;
    • bloating or full abdomen;
    • fever;
    • swelling that appears red or dusky in color and is markedly tender;
    • swelling that does not change in size when crying.


    Your doctor can usually make the diagnosis based on your description and his/her examination of the groin on both sides. The examination may include feeling the hernia and trying to reduce it. If the hernia is not visible at the time of the visit, your doctor may try to bring it out by pressing lightly on your child's abdomen.

    No further tests are usually necessary in a simple hernia.

    Immediate management:

    • None is required if the hernia is reducible.
    • If the hernia is not spontaneously reducing, your doctor may attempt to reduce it by applying pressure to the hernia to return the contents back into the abdomen.
    • If the hernia is irreducible, the blood supply may be cut off and reduction in the office is often not possible. Urgent surgical treatment at a specialist paediatric centre is required.

    Definitive management:

    Once the diagnosis of a hernia is made, surgical repair (a herniotomy) will be performed.

    Is surgery the best form of treatment?

    Yes. Surgery is necessary in all cases, even if it is not yet incarcerated. Herniotomy will prevent the hernia from coming back and potentially becoming trapped. Recurrence rates are less than 1% in an uncomplicated hernia. There is NO non-surgical treatment for hernias. If the hernia is detected and corrected early, aside from a small scar, there should be no long term complications.

    Even a simple hernia carries a risk because it can become incarcerated. Once a hernia is incarcerated, if it is not treated fairly quickly it can lead to immediate life-threatening events including bowel obstruction, bowel perforation and even death.

    Long term complications involving the reproductive organs can occur from delayed or non-treatment. These include the testes in the male and ovaries in the female, both of which can have the blood supply cut off and therefore waste away.

    If your child has a hernia on one side only, there is a small possibility of developing a hernia on the other side. Your surgeon will discuss with you the pros and cons of surgery in the unaffected side to prevent hernia development.

    Advantages include:
    • Your child will only need to have one admission to hospital.
    • Your child will not need to undergo anaesthesia again for a second operation. This is important if your child has risk factors such as prematurity.
    Disadvantages include:
    • The majority of children will not develop a hernia on the other side; therefore the surgery may have been unnecessary.
    • There is a small risk of damage to the testicle and vas deferens (the tube that transports sperm from the testicle) on the other side.

    There is no right or wrong approach. You can discuss this with your child's surgeon and make decisions based on your preferences and what is common practice at your child's hospital.

    How soon does the surgery have to be performed?

    It varies depending on the age of your child and the severity of the hernia. The younger your child is, the earlier it should be repaired. In general, an uncomplicated hernia should be fixed as soon as is practical. If the hernia is incarcerated a more urgent operation may be needed.

    What does the surgery involve and how long will it take?

    It will vary depending on the age of your child, the nature of the anaesthetic to be used and whether one or both sides of the groin will be operated on. Your child will usually be away from you for approximately one to two hours.

    Hernia repair is usually done under anaesthesia. This will be performed by a specialist paediatric anaesthetist. Anaesthetic can be either general (where your child will be asleep) or spinal (where your child will be completely numb from the chest down during the operation). The decision regarding which type of anaesthetic is used depends on each individual and will be discussed with you.

    Supplemental local anaesthetic can also be given either before surgery or at the end during wound closure, to help take away post operation pain.

    The operation involves a small cut (one to two centimetres) in the groin at the natural skin crease. The contents of the hernia sac are emptied back into the abdomen and the sac is tied off. The wound is closed with dissolvable sutures that will not need to be removed.

    Mesh coverings used in adult hernia repair are generally not required in children.

    All wounds heal with a scar. However, becasue the cut is very small (one to two centimetres) and given its position in the lap crease, it will gradually become barely noticeable.

    Are there any risks with this surgery?

    In any surgical procedure, there are risks of anaesthetic side-effects, wound infection and bleeding. The risk of these happening is less than one in one hundred. Complications specific to hernia repair are quite rare. They may include:

    • Injury to the testicle with decreased testicular size in the long-term. However, if a hernia is incarcerated, the testicle may already have been damaged from lack of blood supply and the outcome may not be due to the surgery itself.
    • Damage to the vas deferens, which is the tube that transports sperm from the testicle. Your surgeon will minimize this risk by identifying the vas (often aided by wearing magnifying glasses) and protecting the vas and its surrounding vessels.
    • Damage to the nerve supplying skin sensation over the wound. This will result in numbness over the wound.

    Does anything need to be done before the surgery?

    Your child will need to fast before surgery. The timing and duration of fasting will vary, depending on whether it is a morning or afternoon procedure. If your child is under six months of age, guidelines will be different for breastfeeding or formula feeding.

    You will be sent a letter in the mail a few days before the surgery which will detail the fasting instructions. In the event of an incarceration, surgery needs to be undertaken urgently and the anaesthetist will take extra measures to compensate for lack of fasting.

    What happens after the surgery?

    Hernia repair is usually a day procedure, with your child able to go home afterwards. In some circumstances, your child may need to stay overnight in the hospital for observation. Examples why this might occur include:

    • If the hernia repair was performed as an emergency.
    • Your child is less than six weeks old (or older if born premature).
    • Your child has a pre-existing illness.
    • The hernia was incarcerated and the surgery was difficult to perform.

    When to call your doctor

    After your surgery, you will be given a number to call and some post-operative care guidelines. In general, contact your child's surgeon or the hospital if:

    • Your child develops a fever at or above 38.5ºC.
    • The wound becomes infected (appears red, swollen, or is leaking fluid).
    • You have any other concerns.

    What follow-up is needed?

    • After the surgery your doctor will need to check on the wound and examine your child's testes. This check up may be performed as an outpatient at the hospital; or if you live far away, by a local general practitioner with consultation from a surgeon.
    • You may shower and bathe your child after 24 hours.
    • There is no set time for when your child can return to normal activities. Your child will begin to do things when he or she feels sufficiently comfortable.  However, It is recommended that your child does not play sports for a few weeks.

    Key points to remember

    • There is nothing you did or did not do that caused your child's hernia to develop.
    • A hernia is a bulge under the skin through a weakness or opening in the muscle wall of the abdomen. 
    • Once the diagnosis of a hernia is made, surgical repair (herniotomy) will be performed.
    • In any surgical procedure there are risks of anaesthetic side-effects, wound infection and bleeding. The risk of these happening is less than one in one hundred.
    • Hernia repair is usually a day procedure and your child will be able to go home afterwards.  In some circumstances, your child may need to stay overnight in the hospital for observation.

    For more information


    Developed by the RCH Dept of Paediatric Urology. First published April, 2009. Updated November 2010.

This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital, Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts.