Ultrasound examination of the bowel was once considered inaccurate, based on the presence of large amounts of gas in the intestine, which was one of the main obstacles to ultrasound examination. However, this limitation has been overcome by the removal of gas through intestinal insufflation. With adequate bowel preparation, intestinal ultrasound can visualize the thickness of the intestinal wall, the hierarchy, the narrowing or dilatation of the intestinal lumen, and extraintestinal lesions in the small intestine, colon, and rectum, as well as extraintestinal lesions. Transabdominal ultrasound combined with ultrasonography can play an important role in Crohn’s disease, intestinal tuberculosis, and other diseases in which segmental thickening of the intestinal wall is the main imaging manifestation. It allows screening of the lesion site (mostly in the ileocecal region); it allows evaluation of the inflammatory activity and assessment of the treatment effect by observation of the intestinal wall thickness and blood supply; and it allows observation of the presence of complications such as combined intestinal strictures, intestinal fistulas, and abdominal abscesses. The high prevalence of these diseases is in adolescents, and the recurrence of the disease requires multiple imaging evaluations, and ultrasound has become an important adjunctive examination with its advantages of being radiation-free, economical, and convenient.