Which sign would most indicate dehydration in an infant with a recent surgical procedure (colostomy)?

• A. Increased urine output.
• B. Dry mucous membranes and sunken fontanelle.
• C. Normal weight.
• D. Frequent feeding.

Answer: (B)

In infants, dehydration is best assessed by physical signs of fluid deficit rather than measurements like weight alone. A dry mucous membrane reflects reduced oral hydration, and a sunken fontanelle indicates loss of extracellular fluid and decreased intracranial support from lower circulating volume. In a postoperative infant with a colostomy, fluid losses can be more pronounced, so these objective signs are especially important to recognize early.

The other scenarios don’t point to dehydration as clearly: increased urine output suggests adequate or random diuresis rather than dehydration; normal weight can hide early fluid loss and isn’t sensitive; frequent feeding implies intake is adequate. Therefore, dry mucous membranes with a sunken fontanelle best signal dehydration in this context.