This is the answer. For ELI5: When you put food into your stomach, the stomach stretches. The stretching causes signals to be sent to other parts of the body to prepare it for digestion. Among these signals is the gastrocolic reflex mentioned above.
This causes the movement (motility) of the large intestine and colon to increase, which tends to result in a bowel movement.
JeffroDH t1_ja8bxwn wrote
Reply to comment by dshookowsky in ELI5: If food takes 6-8 hours to fully digest and make it to the small intestine, how come food you eat now affects the qualities of feces from food eaten 8 hours ago (i.e. having to use the toilet soon after eating)? by [deleted]
This is the answer. For ELI5: When you put food into your stomach, the stomach stretches. The stretching causes signals to be sent to other parts of the body to prepare it for digestion. Among these signals is the gastrocolic reflex mentioned above.
This causes the movement (motility) of the large intestine and colon to increase, which tends to result in a bowel movement.