I am a bacterium, and I live with my family in Dave’s colon. We are round microscopic organisms from the Peptococcus species, and we reside in the part of the colon that’s called the cecum.

It’s extremely crowded in there with several trillion other bacteria, and very little space for my two brothers, six sisters and my mother. We don’t have a father because of our asexual reproduction. I am six days old, my two younger sisters are two days old, and my mother is just ten days old, so as you can see, the Peptococcus family has a very short life span.

We stay alive by digesting nutrients that come from further up in the small intestine. We have intense competition for food from other species, particularly the Bacteroides family who make up the largest clan in the colon. These are rod-shaped creatures that live a few nanometers away and vie with us for the choicest morsels. At times, this leaves us with only the onions and garlic that are left over from the Big Mac that Dave eats daily for lunch. Unfortunately, as we gobble up this stuff, a large amount of gas is created, and that, combined with a large Coke, causes Dave to produce a substantial fart about two hours after he eats his hamburger.

One day, there was an eerie stillness in the colon. Lunchtime came, and Dave did not eat his big Mac. Suddenly, a huge flood engulfed the cecum. I hid in a crevice between two colon cells so I wouldn’t be washed away into the toilet where Dave was residing on his haunches. Just when I thought that the inundation had passed, another storm surge hit, and several of my relatives were lost. After that, there was dead silence, and Dave went off to sleep.

The next morning there was a hissing sound, and a large wind came up akin to a tornado. The entire bowel filled with air until I felt the walls would burst. Then I heard a commotion further down in the tunnel. Soon an enormous black snake appeared with a very bright light, and it came straight towards me. I flattened up against the wall, too frightened to move, as the terrifying python slid by and halted before a protruding mushroom-like structure called a polyp. The serpent snared it with a lasso that emerged from its mouth. With a belch of fire, it burned off the protrusion as smoke enveloped the cecum. With a large sucking sound, the excised growth was eaten by the monster leaving a burned out crater where the shiitake had once resided. The monster found another smaller lump, like a barnacle, and this time a large metal jaw appeared and devoured it with one swallow. Finally, to my great relief, the snake retreated.

Afterwards, I surveyed the colon, and as expected, most of the bacteria had been washed away. Three hours later, some onions and garlic came through, and I knew that Dave was back to eating his Big Mac. Within twenty-four hours, the gut was repopulating with new sons and daughters of the Peptococcus and the Bacteroides clans, and our previous conflict resumed.

I inched along the cecum searching for information about this catastrophe, and finally found a wise old nerve cell that had been living in the colon for a number of years. He told me that the snake was not really alive, but was only a mechanical robot that was used to remove polyps from the colon. The procedure was called a colonoscopy, and it would need to be repeated in five years. By then, one hundred and thirty generations of my species will have lived and died, and their progeny will have no memory of the day when the black serpent invaded Dave’s colon.