The "target sign" on CT abdomen indicates concentric rings of bowel within bowel, which is a hallmark of intussusception. This occurs when a proximal segment of bowel telescopes into a distal segment, creating layers seen as alternating densities on cross-sectional imaging. Recognizing this sign is crucial as intussusception can lead to bowel obstruction, ischemia, and necrosis, requiring prompt surgical intervention. Early diagnosis facilitates reduction of intussusception and prevents complications. Other options do not typically produce the classic "target sign" in the small bowel on CT imaging.

Reference: Schwartz's Principles of Surgery, F. Charles Brunicardi, 11th Edition.