Inguinal Hernia

Introduction

An inguinal hernia is a protrusion of abdominal contents into the inguinal canal through the defect at the deep inguinal ring. In children, most of these are congenital in origin. Inguinal hernias are more common in boys. About 10 – 20% of children with a unilateral inguinal hernia may later develop another one on the opposite side.

An inguinal hernia in a child is a common condition and surgical repair is always required as the condition will not heal by itself. Moreover, there is always a risk of sudden entrapment of intra-abdominal contents, a surgical emergency that may lead to ischaemia and even necrosis of bowels, testes in boys and ovaries in girls.

Causes and Risk Factors

The cause of paediatric inguinal hernia is almost exclusively congenital. It results from the failure of a normal developmental outpouching of the peritoneum, the processus vaginalis, to close after birth.

During fetal development, this opening guides the descent of the testis in boys or forms the round ligament pathway in girls.

Normally, it obliterates shortly after birth. If it remains patent, it creates a pre-existing sac that allows abdominal contents to protrude into the inguinal canal with increased intra-abdominal pressure, such as during crying or straining.

This condition is far more common in boys than in girls with a ratio of about 10 to 1 and the incidence is markedly higher in preterm infants, in whom the closure process is frequently incomplete at birth.

Signs and Symptoms

The classical presentation of a paediatric inguinal hernia is an intermittent, soft bulge in the groin or scrotum/labia that appears when the child strains, cries or is active, and then spontaneously reduces when calm or lying down. This child is typically asymptomatic between episodes.

On physical examination, a bulge may be palpable in the groin and is often manually reducible.

This benign picture can change abruptly if the hernia becomes incarcerated. This is a surgical emergency characterized by an irreducible, firm, and tender bulge. The child will become inconsolable and may develop signs of intestinal obstruction, such as vomiting and abdominal distension, which indicate a risk of bowel ischaemia and necessitate urgent surgical intervention.

Diagnosis

Diagnosis of a paediatric inguinal hernia is primarily clinical, based on the classical history of an intermittent groin or scrotal bulge, and confirmatory findings on physical examination. A clinical photo or video provided by the caregiver can be a helpful adjunct to capture the transient bulge. Ultrasound imaging is not part of routine assessment; it is reserved only for cases where the diagnosis is uncertain, particularly in the context of an irreducible swelling where differentiation from other pathologies is needed.

Treatment and Management

Inguinal hernia repair is one of the most commonly performed operations in children. The principle of repair is to close the congenital peritoneum defect at the deep inguinal ring region. The operation can be performed either by traditional open inguinal hernia repair or by laparoscopic repair.

Both methods are minimally invasive and effective to repair inguinal hernia in children.

Open inguinal herniotomy

This is the traditional method to treat inguinal hernias in children.

A small incision is made over the groin region. The hernial sac is identified and separated from the adjacent structures like the vas deferens and testicular vessels. The defect is then repaired by ligating the hernial sac at the deep inguinal ring region. The wound is closed by stitches that will dissolve. In selected cases, the surgeon may choose to examine the opposite side by inserting a laparoscope through the hernial sac into the abdomen. A similar operation will be performed on the opposite side if a defect is found.

Laparoscopic inguinal hernia repair

There are several laparoscopic techniques to repair inguinal hernias in children. Parents should discuss with the surgeons about the technique they use. In general, a small incision is made at the umbilical region and a laparoscopic port is inserted. A laparoscope is then inserted into the abdomen after it is blown up by carbon dioxide. Laparoscopic instruments are then inserted via 2 small wounds at the lower abdomen to perform the repair.

If present, an additional wound shall be made for the repair of an opposite defect.

Follow-up Care

Following the day-surgery procedure for hernia repair, your child will have a small dressing over the abdominal incision. They can resume a normal diet within a few hours after the operation. Pain relief will be provided as needed. We encourage normal walking and gentle activity, but vigorous play, sports, and heavy lifting should be avoided for 2-4 weeks to allow for proper healing. After a period of adequate monitoring in the hospital, your child will be discharged home the same day. A follow-up appointment will be scheduled to ensure a smooth recovery.

References

• Houben CH, Chan KW, Mou JW, Tam YH, Lee KH. Irreducible inguinal hernia in children: how serious is it? J Pediatr Surg. 2015 Jul;50(7):1174-6.
• Chan KW, Lee KH, Tam YH, Sihoe JD, Cheung ST, Mou JW. Laparoscopic inguinal hernia repair by the hook method in emergency setting in children presenting with incarcerated inguinal hernia. J Pediatr Surg. 2011 Oct;46(10):1970-3.
• Tam YH, Wong YS, Pang KK, Tsui SY, Mou JW, Houben CH, Chan KW, Lee KH. Unexpected metachronous hernia development in children following laparoscopic unilateral hernia repair with negative evaluation for contralateral patent processus vaginalis. J Laparoendosc Adv Surg Tech A. 2013 Mar;23(3):287-90.

Acknowledgement

Principal author: Dr Vicky Wong on behalf of Department of Paediatric Surgery

Initial posting: Oct 2026

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