Final answer:
Caffeine, alcohol, spicy foods, and nicotine are common gastrointestinal stimulants.
Step-by-step explanation:
Common gastrointestinal stimulants include caffeine, alcohol, spicy foods, and nicotine. Caffeine is found in coffee, tea, and some soft drinks, and it is thought to block the activity of adenosine, a neurotransmitter that carries messages between nerve cells. Alcohol, spicy foods, and nicotine also have stimulant effects on the gastrointestinal system, but through different mechanisms.