PEDIATRIC RADIOLOGY

Normal Plain Abdomen

    A plain abdomen of a neonate shows gas in the stomach 10-15 minutes after birth, gas in the proximal small bowel 30-60 minutes after birth, gas in the distal small bowel within 6 hours after birth, and gas in the colon and rectum within 24 hours after birth.
    In general, a plain abdomen of a child differs from that of an adult:
    1. A child has less fat than an adult, so the outlines of organs such as the kidneys and psoas muscles are not as well defined as those of an adult. However, we can see the inferior border of the liver and spleen if there is gas in bowel loops adjacent to these organs.
    2. Infants and young children have more gas in the gastrointestinal tract than adults, so we see gas in both the small bowel and large bowel. We cannot differentiate small bowel gas from large bowel gas in infants and young children because there are no mucosal folds. Sometimes the position of the bowel gas helps us to differentiate small bowel from large bowel. If there are bowel loops along the border of the abdominal cavity, they are large bowel. If they are in the central portion of the abdominal cavity, they are small bowel.
 
 

Normal plain abdominal film of a newborn