Final answer:
Serum electrolytes are the key assessment following a colectomy in this scenario.
Explanation:
The most relevant assessment in this scenario is serum electrolytes. Following a colectomy and with the presence of a large amount of fecal liquid in the ileostomy bag, monitoring electrolyte levels is crucial due to potential imbalances caused by the rapid flow of fluids through the gastrointestinal tract.
Urine output is important to assess hydration status, skin turgor can indicate dehydration, and peristomal skin integrity is crucial for stoma care, but in this specific case, serum electrolytes take precedence.
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