There is a strong evidence to support a gut-mind connection that underlies our predisposition to IBS. In other words, those of us who suffer from anxiety and depression are also susceptible to IBS; or, visa versa, those of us who are diagnosed with IBS first are likely to have comorbid anxiety, depression, or other mood disorders.
Anxiety and depression - the most prevalent mental ailments in the US - emerge through a combination of our nature and our nurture, our genes and our environment, with our environment having a much stronger role. Specifically, it is our upbringing: our emotional intelligence is imprinted within the first 6 years of life, and children pattern their emotional intelligence after those that they observe. Emotional intelligence, or EQ, is the factor that can protect us against mental illness, and EQ undergirds all of the basic building blocks we need to become fully actualized human beings: self-awareness, self-love, and self-esteem, from which flow empathy, boundaries, integrity, and humility.
Thus, the seeds of IBS were sowed in your earliest days, lodged in your psyche by whatever energies were being lobbed at your naive heart.
We also know that IBS is a gut motility disorder, a dysfunction in the ability of the intestinal muscles to contract in an orderly fashion and a dysfunction in the ability of our brains to communicate with our gut (brain-gut dysfunction). Deep breathing is beneficial for IBS for the same reason that deep breathing is beneficial for tremors, or lower back pain: the act of focusing on the breath (1) clears mental distractions, thereby (2) allowing us to accept our present state, which, in turn, (3) allows neuromuscular signals to flow unencumbered.
For those of us with the anxiety-prone variant of IBS (there is an anger-prone variant, as well), I hypothesize that the act of deep breathing is painful at first. It was for me. The inhalation of the deep breath is met with such resistance in the abdomen, that the next 10 minutes of the exercise are spent fighting against my body to just let me breathe.
In that way, the treatment - deep breathing - is a fight for space within myself, and it is reasonable to ask if IBS manifests from an internalized lack of space, a deep rooted feeling of not being allowed to breathe, move, think, and feel freely.
Children who experience strict upbringings, or who grow up in a dysfunctional household (where one parent comes down to the level of the child emotionally), are implicitly taught at an early age that it is not OK to be yourself. The message may be explicit: that what you have to say is not welcome, or that your feelings are not legitimate. The continued delegitimization of our feelings as children clearly does not create the conditions necessary for self-esteem and self-actualization. Finally, let's think about the cliche of a child getting a stomachache when they have to go to school: it is a cliche because it is so commonplace, but, in treating it as cliche, we dismiss it. In truth, children get stomachaches because of the gut-brain axis: strongly felt feelings are truly felt in their stomach.
Now, imagine your childhood when you were being told you were not good enough, or being treated like you were less than, or being ignored. For all of us IBS-ers, where do you think you displaced all of those feelings? I suspect that most of us ignored those feelings for most of our lives. If you cannot remember what those emotional and psychological insults were, do not fret: you are carrying that memory inside of you, within the walls of your gastrointestinal tract. All you have to do is breathe deeply to find it.