The small rise in arterial blood glucose concentration that follows the ingestion of a meal is not always reflected in venous blood; after a small early rise, there is often a postprandial fall in glucose to below fasting levels. In situations where the glucose homeostasis mechanisms become overwhelmed by excessively rapid absorption of glucose due to precipitate entry into the duodenum, such as that which occurs after partial gastrectomy, or when insulin secretory capacity is reduced, the glucose pool may expand sufficiently to result in glycosuria.
