Question

What is the difference between metabolic waste and digestive waste?

Answer 1

All the food that we eat is never utilized by the body. The food that is absorbed and taken up is used in various metabolic reactions and in this process, it is converted into certain forms which cannot be further utilized by the body and need to be excreted. Also, some food materials are not absorbed by the digestive system. These get excreted out of the body in the form of faeces.

Complete answer:

Metabolic waste	Digestive waste
Metabolic wastes are produced inside the body. The nutrients absorbed are later used and acted upon by different enzymes to release energy in them.	Digestive wastes are not typically waste.
The different nutrients pass through different reactions within the body. Some of the well-known metabolic reactions are glycolysis, Krebs’s cycle, ETS, etc.	They are basically undigested and unabsorbed foodstuff.
The nutrients are converted into different intermediates and ultimately, certain metabolic end products are synthesized that cannot be used by the body any further. The accumulation of these end products is toxic for the body and hence they are known as metabolic wastes. E.g., Urea and $CO_2$. These wastes are later removed from the body by the Kidney (urea) and lungs $CO_2$.	The food that was unable to get absorbed passes into the long intestine eventually gets converted into faeces and gets eliminated from the anus. Thus, this waste is not metabolized or acted upon by any enzyme.

Note: Metabolic wastes are not only urea and carbon dioxide, but can also be others. Like if a person is taking some therapeutic drugs, then some metabolic forms of that drug (not the active drug form) may be found in the urine. Basically, one major point to be noted is that digestive wastes are
excreted from the anus and the metabolic wastes are excreted by the kidney and lungs. The solutes
and liquids are excreted by the kidney whereas the gaseous ones are excreted through the lungs.