I'm very much interested in what specific processes take place in the gut when we're under chronic stress.
Does any one know the mechanism behind chronic stress as a cause for poor gut health?
There are several mechanisms involved, but mostly it has to do with an overstimulation of the sympathetic nervous system (perhaps you've heard of fight or flight?) When this system is chronically stimulated, it slows the activity of the gut. (Have you ever seen an animal stop to squat and poop when it is running from a predator? Same principle.) Hormone shifts are also very common as we remain in a heightened state of alert. Our bodies are very good at adapting to our surroundings. The problem is that we weren't designed to be under that kind of stress for long periods of time. Then we crave junk because we need to feed the processes that are involved in inflammation...which is actually a protective mechanism for healing from these "fight or flight" bursts. The junk food, of course, causes more gut problems and eventually can start causing autoimmune problems as well.
Stress can cause an inadvertant chronic tensing of the abdominal area which can lead to trigger points along the abdomen and pelvis that can cause constipation, pain, bloating etc
I highly recommend Claire Davies' masterpiece on triggerpoint self-massage. I used the simple yet powerful self massage techniques for everything from frozen shoulder to elbow and calf sports injuries to abdominal issues from gyno issues. Someone recommended it to me years ago on the paleofood forum and it is invaluable. Another great book is Amy Stein's Healing Pelvic pain -- exercises and self-massage.
Robert Sapolsky wrote the book on this entitled "Why Zebra's don't get Ulcers".
Basically, when a stressor is encountered, stress hormones (CRH/ACTH/Glucocorticoids) are released. This triggers the "fight or flight" response, which shuts down (or downregulates) non-critical functions of the body such as digestion, immune response, reproduction, and so on, so the body can focus on the immediate needs of removing the stress. This works great on the savannah when running away from a predator, but not so great when worrying about the mortgage bill all day long. Prolonged stress can lower the immune system, decrease blood flow to the gut, decrease stomach acid production, etc. This leads to gut health issues.
I highly recommend the book.
here are a couple of interesting links i have bookmarked. (i think they're from an answer to another PH thread.. can't find it/don't remember.)
Stress related IBS and fat 2 Answers
Stress questions... I just don't get it. 7 Answers