How long does it take food to pass through the digestive system?  If I
eat a meal now, after how many hours/days will undigested substance
from that meal exit the colon?  Typical duration, or duration range,
of human body's victuals-to-excrement conversion cycle?

Chewing food takes from 5-30 seconds
Swallowing takes about 10 seconds
Food sloshing in the stomach can last 3-4 hours
It takes 3-6 hours for food to move through the small intestine
Food drying up and hanging out in the large intestine can last 18-24 hours
The waste of the food is then stored in the colon, where they remain,
usually for a day or two, until the feces are expelled by a bowel
movement through the rectum.

so, in total, a little less than 3 days

This link is helpful
JB
http://www.madsci.org/posts/archives/may97/860192168.An.r.html