Diarrhea in goats can be triggered by various factors, including dietary changes, parasites, infections, and stress. A sudden change in feed, especially from dry fodder to lush pasture, can disrupt the digestive system. Additionally, young goats are susceptible to infections like coccidiosis, caused by a protozoan parasite, which often leads to severe diarrhea. External parasites like worms can also contribute to loose motions by affecting the goat's overall health and nutrient absorption.