Since hemi-colectomy 2 mo ago, now blood sugar high(despite time release glucophage). is problem that it is not in gi tract long enough to work?

Not likely the cause: Sorry to hear that you had to have the surgery done. Anyhow, the colon is not involved in glucose/sugar absorption and thus the resection is likely the cause of higher blood sugar. Unfortunately diabetes is a progressive disease and people need additional treatment as time progress. With good diet/exercise one can slow down the need, but eventually all diabetics need more therapy if living long...

Could be: Glucophage (metformin) may be absorbed in small intestine? Sugary could be high if your cortisol is elevated due to your adrenals neigh stressed from surgery. Could be your diet is too high in carbohydrates. Best to try low glycemic index carbs.