The Link Between Mind and Gut: A Close Look at IBS

By Meigan Freeman, UC Davis Nutrition Peer Counselor

Did you know that your gut has a brain of its own? Okay, it may not be a whole brain, it can’t paint a masterpiece or write an essay for you, but it does respond to your emotions and eating habits. Have you ever felt butterflies in your stomach before a date or interview? Those “butterflies” are your gut-brain responding to your emotions and they have a profound effect on digestion. Your gut, including the intestines, stomach, and esophagus is surrounded by a set of neurons, called the enteric nervous system (ENS), which controls digestion. Irritable bowel syndrome (IBS) is a gut disorder and provides an excellent example of the interesting relationship between our higher brain and gut nerves.

IBS affects 12% of the population in North America and affects more women than men. The disease is chronic and can be incredibly uncomfortable to live with, causing diarrhea, constipation, cramping, and bloating. IBS is a biopsychosocial disorder meaning biological (certain foods), psychological (emotions and mental illness), and social factors (support system and routine) influence flare-ups. Without one certain cause, IBS is difficult to understand and treat. Thankfully there are some helpful ways to manage this disorder, which I will outline, but first let’s consider how our gut-brain and mind influences IBS.

Our body is made up of two nervous systems, the central nervous system which consists of the brain and spinal cord and the peripheral nervous system, encompassing all other nerves. This series of nerves allows the brain and gut to communicate through neurons and hormones. When the higher brain is stressed, communication can be compromised with increased stress hormones. Studies in patients with IBS showed increased activity in the hypothalamus and amygdala, two important organs which release stress hormones related to our flight or fight response. In particular, the hypothalamus releases the stress hormone, corticotrophin-releasing factor (CRF). Rats with heightened CRF levels show increased anxiety-like behavior, diarrhea, and stomach sensitivity, some symptoms of IBS. These studies indicate that when patients are stressed or anxious their brain releases stress hormones which interact with their gut-brain, resulting in digestion problems and pain. Furthermore, stressful and traumatic events like rape and childhood abuse have lead to digestive disorders, manifesting sometimes weeks and even decades after the event.

If you suffer from IBS, know that there are ways to manage this disorder. Although, I will give some tips below, it is important to speak to your doctor or a dietitian about your individual care. Here are the tips as promised, mostly obtained from Harvard Medical School.

Eat fiber rich foods. An easy way to do this is by simply incorporating more fruits and veggies into your diet and replacing some refined grains with whole grains.
Drink plenty of fluids, especially water and caffeine free tea.
I know it can be difficult, but try to avoid stressful situations as much as possible. Consider talking to a therapist for mental help and clarity. A startling 50-90% of IBS patients have mental illness, mostly anxiety and depressive disorders. Do not be afraid to ask for help.
If stressful situations cannot be avoided, try managing the stress with meditation, yoga, breathing exercises, or journaling. A free yoga resource I personally love is Yoga with Adriene on YouTube. Any other ways that personally help you to relax are also encouraged.
Get regular sleep. This helps keep stress levels down.
Many IBS patients find success with a low-FODMAP diet, or foods low in specific, hard-to-digest, carbohydrates. I highly recommend working with a dietitian on this diet, but I included an image below for reference of foods to avoid and enjoy.
Try keeping a food diary to see which foods give you more digestive distress. Use the avoid section on the image below for the most common foods that cause digestive issues.

I hope this article was helpful to you, especially those with IBS. As you can see, IBS is a complicated disorder due to the intertwined feedback of mind, gut, and body. Much research is still needed for how mental stress can manifest as physical symptoms, nevertheless you can get help with this disorder by working with a doctor and dietitian.