What is a common early sign of a small bowel obstruction?

Recurrent vomiting of bile-stained fluid is a common early sign of a small bowel obstruction due to the anatomy and physiological processes involved in this condition.

In a small bowel obstruction, the obstructed segment prevents the normal transit of intestinal contents. This leads to a buildup of fluid and gas proximal to the obstruction, causing distension and increased pressure within the bowel. As the obstruction persists, the contents will eventually back up into the stomach, resulting in vomiting. Importantly, if the obstruction is distal enough, the vomit can become bile-stained, as it contains components from the duodenum—the part of the small intestine that receives bile.

Other symptoms, such as abdominal pain, distension, and constipation, may also be present. However, the recurrent vomiting of bile-stained fluid is particularly characteristic as it indicates that the obstruction is preventing nearly all material from moving further along the digestive tract, thus leading to the accumulation and eventual vomiting of bile-containing fluid.