Non-fasted insulin 59 when b/s is 86, and in the 18 when b/s 68, 12 when b/s Is 53. High enough to suggest insulinoma? Or congenital hyperinsulintima

Hypoglycemia. Insulinoma is extremely rare, but usually not a hard diagnosis to make once it is suspected. The blood sugar and insulin levels must be done fasting. Post prandial testing and glucose tolerance tests are worthless in making this diagnosis. You should see an endocrinologist.