Stress suppresses digestive system. Roughly speaking, it redirect energy from stomach into muscles. Instead of becoming sleepy and relaxed to digest food, the a

Stress suppresses digestive system. Roughly speaking, it redirect energy from stomach into muscles. Instead of becoming sleepy and relaxed to digest food, the animal becomes focused and ready to run from a threat. This is an evolutionary mechanism to let the animal escape from a predator. However, if the stress is permanent and never goes away, the digestive system become suppressed for way too long and gets damaged.