A Quick Tour of the Sphincters

One morning, as I was waking up from anxious dreams, I felt more physically relaxed than ever before. But was also aware of something dreadfully amiss. As I lay on my back and lifted my head up a little, I slowly opened my eyes. I looked towards my feet and was not confronted with a brown, arched abdomen divided up into rigid bow-like sections. Nor did I have numerous pitifully thin legs.

Thank God! I was not Kafka’s Gregor Samso who discovered that in bed he had been changed into a monstrous dung beetle. But something was definitely wrong. I was no dung beetle but there was a powerful scent of dung in the air.

And though I had my normal two legs, they looked out of focus. As I became fully awake I noticed more distressing details. I had a strong burning sensation in my chest. Another separate sharp pain in my gut. My upper legs were cold and wet and there was that strong smell of feces in the air.

I roll gingerly onto my side and sit up on the edge of the bed. The pain in my chest and gut intensifies. The bright morning light streaming through the window is painful. It hurts. To see more clearly, I straighten and then look down between my legs and blurrily discern the source of the wetness and foul odor – I have completely wet myself and my pajama bottoms were also brown with fecal matter.

What’s happened to me? This was no dream.

Well, this isn’t a dream but, with apologies to the opening of Franz Kafka’s Metamorphosis, it depicts what would happen if all my anatomical sphincters simultaneously stopped working. The sphincters, those small and usually ignored ring muscles, perform critical functions that shape vital aspects of our lives and culture.

The painful sensitivity to light and visual blurriness? If the iris sphincter muscles that control dilation of the pupils fail, your eyes cannot adapt to varying degrees ofight and you will be hypersensitive to fluctuations in light and have difficulty focusing.

That sharp pain in your upper chest? The cardio or lower esophageal sphincter is a one-way valve which prevents gastric juice in the stomach from flowing back into the esophagus. Mild forms of this failure of this sphincter produces heartburn. Total failure would destroy the esophagus. And kill you.

A burning sensation in your gut? Failure of the sphincter at the bottom of the stomach, the pyloric sphincter, which opens to allow the passage of small amounts of acid into the duodenum when the stomach has finished its work. If this sphincter failed, too much acid would get through and eat its way into the wall of the duodenum causing duodenal ulcers – and constant pain. This would be exacerbated by the opening of the Sphincter of Otti which controls the flow of bile from the gall bladder into the gut.

Wetting and fouling yourself? Now we’re getting to the better-known sphincters. The ones we can control voluntarily - the big kahunas of the sphincter family: the urethra that controls the flow of urine and the anal sphincter – of ‘your so anal’ fame. If these two ring muscles completely relax – you’ve got a mess.

As this quick tour of sphincters from top to bottom shows, complete failure of all sphincters would be disastrous and quickly prove fatal. But the story of how each of these amazing muscles perform – usually unbidden and beyond our control – to shape our lives and even our cultures, contains many surprises. And some amusing information as well. We’ll be digging a little deeper into each of these rings.