Believe it or not, there is also another real reason why straining at stool is dangerous… for people with heart problems.
When I was a junior resident in surgery, we were taught to perform rectal exams on every patient that came to be surgerized. We did not like this duty, neither did they, so our seniors and superiors impressed on us long and soundly that it was imperative and not optional. The only break we got came when it was a heart patient. If a man was three months or less out from a heart attack, we were excused from the digital rectal exam. Why? Because it was known to bring on arrhythmias. You could start a new heart attack – or worse, a “code” – by doing a digital rectal.
This is because of a vasovagal response, meaning a response by the blood vessels to an impulse directed from the vagus nerve. The vagus, the name of which means “wanderer”, is a cranial nerve that starts in the brain, exits the skull, wraps around the esophagus, sends sprigs off to innervate the heart, heads down over the stomach, and terminates with at least one branch in the anal sphincter. If you get your finger in there and squidge around, or if hard stool passes the sphincter with enough force, sometimes you trigger a reaction in the nerve. It’s known empirically that this sometimes stops hearts. I don’t know the exact how or why, but I don’t have to know. Empirical is good enough for me.
And, as support for empirical evidence, as a medical examiner I not infrequently see dead people with the famous Ring of Elvis – Johnny L.A. is quite right about that – that is, the mark of the toilet seat impressed upon their buttocks into the livor mortis. Death while peeing is comparatively quite uncommon.
If you are young and healthy and have no heart problems, straining at stool will give you nothing worse than hemorrhoids. If you have a heart problem you don’t know about, straining at stool could give you a chance to find out. Remember, for between a fifth and a quarter of all people with coronary artery disease, the first symptom is sudden death.
You’re not middle-aged are you?