So, I don’t have experience with this exact issue, but I do have GI issues in my upper GI tract/esophagus (so, other end), and there has been a lot of discussion about anxiety and I have treated for anxiety in addition to the physical problems. Here is what I’ll say on it:
First, there absolutely can be a mind-body connection in all of this, which I have learned painstakingly after years of uncertainty and being misdiagnosed (and, initially thinking it was all a bunch of woo woo nonsense). What was particularly bad with my issues (you can think of it as reflux type issues) is that I would end up in a self-fulfilling anxiety spiral. So, I would feel bad, which would make me nervous and convinced that I had some sort of stomach/esophageal cancer, and then that would make me anxious, which would then make my physical symptoms start flaring up even more.
Second, related to the first. Anxiety can make these issues worse. So whether or not he has IBS probably shouldn’t be the doctor’s only focus. If the doctor isn’t giving him medication or tools to help calm this down, which it doesn’t sound like the doctor has from your pose, then he probably needs to see a new doctor. I ultimately ended up at a tertiary specialist for GI motility issues and diagnostics, and one of the first things she did was give me some medication for nausea and diarrhea. She didn’t do this because that medication was going to solve my problems. She gave it to me because she said, “listen, sometimes feeling this way makes you feel anxious, which makes it worse, so this should put your mind at ease that you have something you can take if you start feeling bad.” Honestly, just having that did help ease my anxiety while we sorted out what was going on. I’ve never even opened the box of medicine for diarrhea, but just knowing I had it if I needed it helped immensely. So, his doctor should be helping him with these types of things, and hopefully not just dismissing it as “anxiety, just get over it.”
Third, I started seeing a psychiatrist who works specifically with GI patients, because what I ended up having is cured by (wait for it) diaphragmatic breathing. I kid you not! This started my long path down to the mind-body connection and now I’m a total believer. What I learned was this – because of COURSE I kept insisting I wasn’t anxious – I, emotionally, was coping with anxiety pretty well. But, I was sending lots and lots of physical stress signals to my body, and it was manifesting in GI symptoms. So, I’ve started doing: yoga, meditation, lots of deep breathing. In general this has reduced so many of my symptoms, and I know how to send calming signals to my body now. I was barely hanging on three years ago, and now I feel better than ever! (I watched some TED talks on the power of diaphragmatic breathing, and it really improved my understanding of how it interacts with our nervous systems, if I can find them, I’ll share the links below.)
Lastly, there are medications he can take that either relate to anxiety or to nervous system problems. I have been on a medicine that helps to down-regulate my nervous system, because some of what I have is caused by overactive nerves (i.e. nerves are overactive and keep opening the muscle that closes off the esophagus and stomach), and it has helped so tremendously and after 18 months on it, I am weaning off. Again, if his doctor is not exploring these options, I would suggest another doctor.
Good luck to you and him! This is tough to deal with, and it is so unfortunate that patients really have to advocate for themselves sometimes. (*note – I’m not a doctor, obviously, all of this is just my explanation/understanding of what I’ve dealt with.)