Once home, I googled autism awareness, bumper sticker, and entered a whole world of autism products. Bumper stickers, of course. But also tee shirts, jewelry, stickers (I am someone with autism), mugs. Eventually, I exited even more perplexed than I entered.
In general, the digestive system is controlled by both nerves and hormones. The nerves that control digestion are in the submucosa layer of the tissue and in between the muscle layers of the walls of the organ.
The liver and pancreas both play important roles in digestion. The liver produces the bile (required for digestion), which is carried into the small intestine by the bile duct and the pancreas secretes the pancreatic juices that also aid digestion and nutrient absorption.