Do a acoelomate have a simple sac like gut cavity?

Acoelomates, such as flatworms, do not have a true gut cavity; instead, they possess a gastrovascular cavity that functions in both digestion and nutrient distribution. This cavity is more sac-like compared to the complete digestive systems found in coelomates, but it has a single opening that serves as both mouth and anus. Overall, the digestive system in acoelomates is simpler and less specialized than in organisms with coelomic cavities.