Final answer:
The most suspicious finding of Crohn's disease during a physical exam would be symptoms such as abdominal pain, diarrhea (potentially with blood), fever, weight loss, and possibly associated skin manifestations like pustules around the elbows.
Step-by-step explanation:
The nurse conducting a physical exam of a child with suspected Crohn's disease would find several signs highly suspicious of this condition. Some of the classic symptoms might include abdominal pain, diarrhea (which may be bloody), fever, and weight loss. Given that Crohn's disease can affect any part of the gastrointestinal tract, the nurse might also be on the lookout for skin manifestations, such as pustules or crusts around the elbows, indicative of bowel-associated dermatosis-arthritis syndrome (BADAS), which is sometimes associated with Crohn's disease. If the child presents with these symptoms, it would warrant further investigation through a colonoscopy to visualize directly the colon and ileum for confirmation of Crohn's disease.