I think there's a lot of information about diet out there. I'm not going to tell you it won't help but what will you do if it happens while have a clean diet? Essentially with TMSers it seems people don't think it's TMS because they can't really fathom that the brain could be behind this or stress or anxiety. It took me a long while before I could believe it also. I Also did diets, whole thirty, Fodmaps etc. Nothing changed for me at all except I now had to deal with the notion that I inadvertently created ideas of bad and good foods. There are good and bad foods already but I created an association that they would hurt me.
Let's look at what non structural IBS is. It is either moving the bowels too quickly or too slowly. Muscles of any kind, including those in your Intestines, have the same basic function. They can either relax or constrict- that's it! There are no other special functions. The name TMS is tension (constriction) Myo (muscle) itis (recurring) so it seems apt to call it TMS. The difficult thing is that we have less direct control over how muscles in our gut respond to our messages of safety.
The limbic system, the emotional part of the brain is linked to thr amygdala. They work together to create emotions and responses to threats and or emotions and create associations. The limbic system does not respond to language. It speaks the language of sensation, emotions, images. All of the TMS approaches cover these things to show our brain that we are safe.
How one can get stuck: when we respond to stress with an emotion say fear, it can affect many things and have a physiological response knots in stomach or tightening muscles. The problem occurs when we respond to this response with fear. Now you have created a fear of a fear response and that creates more physical symptoms and you react with more fear and it reacts with more symptoms. This is the cycle.
I see no harm in having a multi-faceted approach to IBS. But Believe your doctor, he went to med school, we didn't. Anxiety or health anxiety is really sneaky and says to us what if he missed something? Or there's no way this is just tense muscles. TMS can get weird.
Be well, I hope you get relief soon.