What does bilious emesis usually indicate?

Bilious emesis, which refers to vomiting that contains bile, is an important clinical sign. The presence of bile in vomitus typically indicates that there is a blockage in the gastrointestinal tract, often seen in cases of bowel obstruction. When the normal flow of intestinal contents is impeded, bile that would normally proceed into the intestines can back up and be expelled through vomiting. This is in contrast to normal gastrointestinal function, vaccinations, and increased appetite, where bile would not be present, thus reinforcing that bilious emesis is more suggestive of a pathological condition such as a bowel obstruction.