A bowel obstruction is a condition in which the normal passage of intestinal contents is partially or completely blocked. On ultrasound, signs of bowel obstruction include dilated, fluid-filled loops of bowel, increased back-and-forth movement of bowel contents called the to-and-fro sign, and collapsed bowel segments beyond the point of blockage. Ultrasound can also sometimes identify the cause of the obstruction, such as a hernia, intussusception, or mass. While CT scanning is generally considered the most comprehensive imaging tool for bowel obstruction, ultrasound is valuable as a first-line study, especially in children and pregnant women where avoiding radiation is important.
Sonography Term