Jamie Lee Curtis seems comfortable talking about her bowel habits, but most of us keep these matters to ourselves. If toilets could talk, they'd say that 10-15 percent of the population struggles with recurrent episodes of abdominal pain, bloating and cramping, combined with bowel habits that bounce around between constipation and diarrhea. This collection of symptoms is called irritable bowel syndrome, and though it won't kill you, it has the potential to send your life literally and figuratively into the toilet.
There's a fictitious but undeniable hierarchy among the seven human organ systems, and the gastrointestinal ("GI") system seems to occupy the bottom rung. As the name suggests, we often think of the human gut as a simple gutter that runs from stem to stern, pulling nutrients off a gravity-fed conveyor belt and then dumping out whatever's left. The lofty brain thinks, the mighty heart pumps, the savvy kidney filters, the gut poops.
But the facts suggest otherwise: The gut -- the esophagus, stomach, small intestine, and colon -- is extremely complex. Its muscular walls are richly imbedded with nerve fibers that help it contract in coordinated waves that mix and move food. Myriad chemicals, neurotransmitters, and hormones exert local control over the digestive process and interact with the liver, pancreas and the rest of the body as well. When we eat or drink, we expose ourselves to infectious ilk and toxic chemicals, so the gut has the difficult task of allowing the good stuff to pass through the lining of the intestine and into the bloodstream (i.e. absorption), while keeping the bad stuff out. For that reason, the gut possesses a heavily-fortified immune system to fend off any unwanted intrusions; unfortunately, that can also lead to food allergies. To complicate matters, the colon has millions of healthy bacteria (not an oxymoron) that live symbiotically with us. It's a guest list that can be altered, sometimes drastically, by antibiotics and even by our food choices.
So the gut doesn't deserve its bottom rung status; in fact, there's a very clear and rich connection between the lofty brain and the not-so-lowly gut. This occurs directly through nerves, and indirectly through stress-related chemicals like cortisol and adrenaline.
Although everyone is stressed out to some degree, and everyone has occasions where they feel their negative emotions in their gut -- "worried sick," for example -- those with irritable bowel syndrome (IBS) seem to have an enhanced sensitivity to the feedback that the gut sends to the brain. As a pattern of gut dysfunction sets in, IBS sufferers can sometimes fall into a shell-shocked state, where even a small amount of cramping can escalate into big worries: Is this going to be one of those diarrheal weekends? Is the pain going to ruin this important business trip? They've developed a conditioned fear response, a pre-programmed neural circuit in their brain that begins firing at the slightest hint of gut trouble, be it real or perceived (to the brain, both are equally real). They are at war with their gut, always fighting it.
Which might make the title of a new book about IBS called Trust Your Gut seem like Jesus' injunction, "Love your enemies." Really? And yet the book's authors, physician Greg Plotnikoff and psychologist Mark Weisberg, mean exactly what the title says: They train their IBS patients to spend time calmly paying detailed attention to their bowel symptoms. The goal is to allow patients to recognize two things: first, that without the associated fear response that can escalate things, most gut symptoms harmlessly pass; and second, that sometimes these symptoms are the gut's way of showing the patient that his or her mind is a whole lot more stressed out than it will admit.
Plotnikoff and Weisberg call this technique neurohormonal retraining:
This important exercise sends a new signal to structures deep inside your limbic brain. You are telling the amygdala and related brain structures, "This sensation is no longer a threat." As you repeat this exercise, the limbic brain starts to signal to the nervous system that these sensations of pain, pressure, and bloating are not a cause for alarm. When this happens, there is a change in the cascade of neurotransmitters and neurohormones that communicate with the gut.
As the book points out, it would be a mistake to suggest that irritable bowel syndrome is all in a patient's head (although that's what patients often hear when their initial workup returns negative). There's a review paper in the New England Journal of Medicine that chronicles all of the physiological abnormalities that have been found inside the gut of IBS sufferers -- increased inflammation, microscopic leakiness of the lining of the intestines, hypersensitive pain receptors, and altered bowel flora, to name a few.
Trust Your Gut tries to bring some clarity and relief to a disabling and complicated disease that we still don't understand very well. We can say this: If you have IBS, it's not all in your head. But as with all humans, your head and your gut are intimately connected.
Disclaimer: I am a colleague of Dr. Plotnikoff's (we work in different areas of the same medical campus), but I have no financial interest in the book or in any other matter with him or Dr. Weisberg.
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