A hernia, commonly known as a hernia or small intestine, has the same meaning as the English word “hernia” and refers to an organ or tissue in the body that leaves its normal anatomical location and enters other parts of the body through a congenital or acquired orifice. In layman’s terms, like in the abdomen, there is a “hole” in the belly where the small intestine or other tissues can be drilled into. In the human body, hernias can occur in most places where there is a cavity, such as cranial hernia, diaphragmatic hernia, inguinal hernia, incisional hernia, etc. (The picture below shows a patient with a huge umbilical incisional hernia) But the majority of hernias we see (more than 90%) are inguinal hernias. The common people only refer to inguinal hernia as hernia probably because in terms of presentation, the gas over water sound (caused by intestinal peristalsis) is felt on these protruding masses or in the enlarged scrotum, and also the sensation of gas in the hernia “gas” can be distinguished from testicular sphingomyelia in the scrotum (commonly called “water egg”). The hernia can also be distinguished from a sphincter of the scrotum (commonly called “watery egg”). Inguinal hernias are common in men and can occur at all ages from birth to old age, with a lifetime probability of more than 20% in men, making inguinal hernias a common and frequent occurrence. Inguinal hernias also occur in women. Only the incidence is lower at about 3%. （Why is “small bowel gas” (hernia) more common in males? This is because during male development (before and after birth), the testicles slowly descend from the lower back to the scrotum, and during this process, a potential gap (called inguinal canal) may be left at the base of the thighs, which eventually becomes a hernia due to the combination of factors such as human evolution into a standing creature and abdominal pressure. What are the symptoms of a hernia? A hernia (more than 95%) is a visible and palpable disease. You may find by chance a small lump at the base of your thigh in the shower, which does not hurt or itch. It protrudes when standing and disappears after sleeping (lying on the back), and can also be slowly pressed back into the abdominal cavity by hand. However, sometimes there is a sudden increase in size, accompanied by significant pain, and it is difficult to push back into the abdominal cavity. This may be an “incarcerated hernia” in which the small intestine or other tissues are stuck in the opening of the hernia, affecting the peristalsis of the intestine and leading to intestinal obstruction (abdominal pain, bloating, vomiting and stoppage of the anus). “strangulated hernia”, which may have peritonitis, sepsis and even life-threatening. Therefore, when the hernia has obvious symptoms, prompt medical consultation should be made to avoid delaying the treatment. (Figure 3 below shows a schematic diagram of small intestine stuck in the hernia sac)