During bowel rest, mucosal atrophy is best described as which of the following?

• A. Mucosal hypertrophy
• B. Mucosal atrophy
• C. Hyperplasia
• D. Regenerative growth

Answer: (B)

Disuse of the gut during bowel rest reduces luminal stimulation, causing thinning of the mucosal lining. This mucosal atrophy involves shortened villi and a smaller absorptive surface area, leading to decreased absorptive capacity and altered barrier function. It is not mucosal hypertrophy (thickening), hyperplasia (more cells), or regenerative growth (repair after injury), which describe other tissue responses. Recovery can occur with refeeding and reestablishment of luminal flow, though it takes time.