Which symptom may indicate a small bowel obstruction?

Abdominal pain is a hallmark symptom of a small bowel obstruction. This type of obstruction can cause significant discomfort due to the increased pressure and stretching of the bowel as contents accumulate proximal to the blockage. The pain can be crampy in nature, often reflecting peristaltic movements as the intestine attempts to push the stagnant content through the obstructed area.

In contrast, weight gain is typically not associated with small bowel obstructions, as the obstruction may lead to nausea, vomiting, and decreased oral intake, contributing to potential weight loss or at least weight stability rather than gain. Lower back discomfort is less specific and does not directly correlate with the gastrointestinal issues involved in a small bowel obstruction. Lastly, while headaches can occur for a variety of reasons, they do not serve as an indicator of a gastrointestinal blockage. Thus, abdominal pain is the most relevant and significant symptom to consider in the context of a small bowel obstruction, aligning with the physiological changes and clinical presentation associated with this condition.