Which symptom is most commonly reported with small bowel obstruction?

Nausea and vomiting are the most commonly reported symptoms of small bowel obstruction due to the accumulation of digestive contents that cannot pass through the obstructed segment of the bowel. As food, fluids, and gas back up, the distention of the bowel wall occurs, stimulating the vomiting reflex as the body attempts to relieve the pressure and discomfort. This can lead to electrolyte imbalances and dehydration, which can further exacerbate these symptoms.

In contrast, while constipation can occur, it is usually noted if the obstruction is partial or if the obstruction leads to a complete stoppage of bowel movements. Diarrhea is uncommon because the area of obstruction typically prevents digested material from reaching the distal intestines, leading to a lack of liquid stool. Fever may or may not be present depending on the underlying cause of the obstruction, such as infection or inflammation, but it is not a direct symptom of small bowel obstruction itself.