Can you help me as I'm a Personal Trainer with my own health problems? :-(

If you check the logs, you will see a big entries on this topic. As you know, IBS is a general term with a long list of symptoms. Do realize that most diseases, conditions, etc are named so a drug can be described. The naming is based on a list of symptoms. Many symptoms, though, are part of many conditions/diseases.

As for your estrogen deficiency, as no man is an island, no symptom stands alone. I have learned in my time that you do not have to heal everything to feel better overall but just start on something most likely to achieve some success.

I would have guessed by now that you have been tested for Celiac. If not, B-line and get that test...

IBS has also been dubbed by a colleague of mine Irritable Brain Syndrome. I bring this up to show that the brain and gut connection is implied. Often, side effects will include sleep problems sometimes caused by B-vitamin(b12 mainly) deficiency and further exacerbated by lack of absorption of minerals like magnesium. This in turn fries your adrenals from overstimulation and eventually leads to low energy. Add some meds like Ambien and you create the perfect storm. etc, etc...

If it were me, I would go after my gut problem before estrogen to stop the most immediate IBS related issues. We don't have to discuss the list. Think "gut rebuilding". A specialist can help you but look for one with good references-this will take some time.
Look at Md's but do consider a ND (Naturopath).

There are lots of ways to start this. All the cowriters here have varied opinions. If it were me having the problem, I would supplement this way.
Wake up:20g of L-glutamine in a bit of water upon waking
Breakfast(eat foods not sensitive) then right after probiotics/multi vit, fish oil
Lunch: Light meal w rice protein based shake, glutamine, added immunoglobulins, probiotic
Mid afternoon: Light protein and vegetable meal, Mg supplement, fish oil
Dinner: Non sensitive foods, Mg supplement, fish oil, probiotics
Later: Non caffeine Valerian tea

I would consider brands like Xymogen, Metagenics, Douglas labs and Poliquin...
There are no good, cheap supplements.

Thanks for this - I'd read about magnesium being helpful to this before so this has confirmed it to me so will get on it. Have you any recommendations on a rice based protein shake as this is definitely an area where I've struggled in the past up til now to find a protein which doesn't disagree with me...

My faves..

Mg---Ubermag by Poliquin Nutrition (start w 6 pills/day) 2 t.i.d
Take a look at this: Xymogen Opticleanse, Inflampx by Poliquin

I think that you really need to see a dietitian and would deter you from trying supplements without guidance from someone trained to work with individuals with your medical conditions because it sounds like you might be at risk for being deficient for a lot of nutrients and you want to be sure that you are receiving appropriate nutrition to help you feel better. I urge you to harass your physicians; after all, they are working for you and providing you with a service. Bother them, be pushy, if you have to, get a second option and seek out another physician.