I have to say your quite elaborate description provided a welcome humorous interlude during a long afternoon at work! However, from a medical perspective, I don't think delaying the 'morning evacuation' so to say for 10-12h does any discernible difference to the level of possible toxins accumulating in the bowel. The link between evacuation and colon cancer relates more to a general pattern of infrequent stools in some Western cultures compared with others whose diets result in more frequent movements.
The 'hazards' associated with forced delay of bowel emptying probably relate more to the development of hard stools and its attendant complications (constipation, haemorrhoids, anal fissures).
For those who do suffer from such issues, perhaps the
Squatty Potty may be of use?