Hello, first of all please don't take my question as a sneering one. I would like to know if there is any fecalic value in feces. I already know that poop contains both digested and indigested matters. I also know that there are some kinds of bacteria that consume some of indigested matters. It is clear for me that the caloric value may differ depending in the amount/kind of food a person consumes. But still, are there any ways of meaduring a caloric value of feces? For instance, if after relieving myself and making sure that my stomach is empty, I ate an apple the caloric value of which is equal to 50 calories, what will I get in my feces after? I didn't manage to find any information on this subject and I will be grateful for having found the answer here.
Thank you a lot in advance!

much of the nutrients in the food we consume will be absorbed (sugars, fats and protein). what is left is roughage and cellulose and that will very definitely have measurable calorific value. descriptions of the techniques for measuring that are available if you google the term