If a patient had subtotal colectomy w/ileostomy placement resulting in short bowel syndrome for over 13yrs, could they have their ileostomy reversed?

It depends : This is a difficult question to answer without more data. Assuming they had some sort of small bowel resection and truly has "short gut," then reconnecting to a rectal stump will likely not improve the condition, as the rectum does not provide adequate nutritional absorption (mainly just water resorption). This needs to be discussed with a general surgeon along with radiographic evaluation.