What disorder is characterized by the colon's inability to absorb water?

The disorder characterized by the colon's inability to absorb water is diarrhea. This condition leads to the passage of loose or watery stools, which occurs when the colon does not effectively reabsorb water from the waste material. As a result, the excess water remains in the stool, resulting in frequent and urgent bowel movements.

In contrast, constipation occurs when the colon absorbs too much water, leading to hard and dry stools that are difficult to pass. Gastroenteritis, while related to digestive issues, involves inflammation of the stomach and intestines and is typically associated with both diarrhea and vomiting. Appendicitis refers to inflammation of the appendix and is not directly related to the absorption of water by the colon. Thus, understanding these conditions helps clarify why diarrhea is the correct answer in this scenario.