Everything organic is just one more thing that can lead to death, so lose it. If Morton had his way there's probably not enough left of him to take a shit. The easiest thing would be whatever toxins in his blood are processed and scrubbed by the cybernetics from his remaining circulatory system. They show his food, so they let him keep his stomach. Some type of port on the suit is used to offload that waste. He wouldn't need an endocrine system this way. There would just be some fluid trap in the "suit" holding biowaste. Not the same as urine, but still functionally a waste product.