Why are patients with ileostomy at risk for hyponatremia?

• A. The sodium content of ileostomy output can be as high as 120 mEq/L; Hyponatremia can result when fluid replacement does not contain adequate sodium to correct for ileostomy losses.
• B. Ileostomy output is mostly potassium
• C. Ileostomy decreases water losses
• D. Ileostomy outputs are low in electrolytes

Answer: (A)

Ileostomy bypasses the colon, which normally reclaim's water and a lot of sodium. The effluent from an ileostomy can contain substantial sodium, sometimes up to about 120 mEq/L, which means large sodium losses in the output. If fluid replacement does not provide enough sodium to offset these losses, the body’s sodium level can drop, leading to hyponatremia. The key idea is that the high sodium content of ileostomy drainage requires adequate sodium in rehydration fluids to prevent hyponatremia. Ileoostomy output is not primarily potassium, it does not decrease water losses (it increases them), and it is not low in electrolytes, which is why those options aren’t correct.