I suffered the way you do too. Hope you can find wisdom in my experience.
The stomach problem: twisting in pain, stomach as if about to explode, burning and stinging sensation, feeling of throwing up, bloating, bowel movement disorder, sometime frequently going toilet but nothing comes out or only little yet painful and etc.
I always experience that every time I have a church project being conceptualized. The worst was when I have the desire to put up a prayer group.I pursued despite of the trouble. I suspected it was devil’s work trying to stop me because it even block my understanding as I compile what prayers I should include in the prayers. It took me about a month to compile for the prayerbook in intense suffering
Not minding the problem, I approached our parish priest and told about my plan. When he said yes, my pain diminished about a half. My problem with the understanding was solved by making a good confession. But as we started with the prayer devotions, my pain and suffering stopped as if nothing happened. That, I am certain, it was the devil who is causing me the trouble.
Another disturbing experience was during our preparation for the dedication of our newly constructed big church. While at work, I was experiencing a disturbing feeling, that something will happen. Like in any other experiences, I didn’t mind the suffering, I just go on with my responsibility. The afternoon after the dedication, we received news about the stomach troubles of almost all our guests. During the night, I suffered my pain. I just thought it was just an ordinary Loss Bowel Movement. The second time I went back to the comfort room, I was certain it was not just an ordinary LBM. My stomach moved so violently painful but no bowel came out. As if something is about to come out ripping my stomach. I decided to go back to my room and took a holy water. As I prayed and made sign of the cross in my stomach with the holy water. The pain and the contraction stopped. That moment, I knew it was the devil causing the trouble. So, I prayed for the rest of our guests. I was delighted to know that their sufferings stopped in almost the same time my suffering stopped.
You are in the way of returning to the faith… as in my case, trying to do good things- the stomach and bowel problem sets in. I continued in my plans; talk to the priest, have good confession, prayed and applied sacramentals and my problems disappeared.
In your case, the doctors can not categorically point out whats causing you the trouble. What makes more intriguing in your case is that, it only appears when you are trying to go back to the church or praying. And if that is the case, the devil is trying to stop you.
Like the way I did, I pursued every good things I planned to do. I just pursued my way. Continue though to visit your doctor. Visit also your priest. Like in my case, just telling my plan of a prayer group to our priest diminished my suffering. Tell your priest too and affirmed your plan to go back to the church and prepare for a confession. It might help you. Just continue you plan to go back to the church, like in my case, my suffering from the devil just ceased.