Clean Colons in Nature

Many centuries ago the natives of India noticed that certain birds of the ibis family - a long-billed bird - would return from journeys into the interior in a wretched condition, which was due either to their eating some berry which was very constipating, or else having been where there was no water to drink - possibly both.

This bird would reach the rivers in an almost exhausted condition, scarcely able to fly from its weakness.

The bird would fill its bill and mouth with water from the river and then, inserting the bill into the rectum, would inject the water into the bowel, which would relieve it in a few moments.

The bird would repeat this several times, until the bowel was completely emptied, and would then sit around and rest for a few minutes until its vitality was restored, when, after drinking freely from the river, it would fly away as strong and active as ever.

Hatha Yoga - The Yoga Philosophy of Physical Well-Being
Yogi Ramcharaka