At that time a monk who had been born as a brahmin did not want to wash after defecating, thinking, “Who would touch this foul, stinking stuff?” As a result, a worm settled in his rectum. He told the monks, who said, “So you don’t wash after defecating?” “That’s right.” The monks of few desires complained and criticized him, “How can a monk not wash after defecating?” They told the Buddha. Soon afterwards he had the Sangha gathered and questioned the monks: “Is it true, monk, that you don’t wash after defecating?” “It’s true, sir.” … After rebuking them … the Buddha gave a teaching and addressed the monks: “When there’s water available, you should wash after defecating. If you don’t, you commit an offense of wrong conduct.”

At that time the monks used the restrooms according to seniority. Junior monks who had arrived first had to wait to defecate. Unable to hold out, they fainted and collapsed. They told the Buddha. … “Is it true, monks, that this is happening?” “It’s true, sir.” … “The restrooms shouldn’t be used according to seniority. If you do, you commit an offense of wrong conduct. You should use the restroom according to the order of arrival.”