Small bowel gas, i.e. inguinal hernia, can usually be diagnosed by physical examination and ultrasound, and the specific examination methods are as follows: 1. Physical examination: the fixed sign of inguinal hernia is a reversible mass protruding from both inguinal regions. When the hernia sac encounters adhesions that cannot be retracted, it may develop into a refractory hernia. If left untreated, the hernia contents may become stuck in the hernia sac and lead to its necrosis, and patients are advised to undergo surgery. 2. Ultrasound: Some patients with hernia can be observed to have abdominal wall defects by ultrasound examination of the body surface swelling.