You can speak to anyone here, and we all have stories about persistent bowel problems. But since I believe that merely discussing our experiences of anxiety symptoms itself is not very effective in controlling anxiety, I will try and get straight to it since you have massive fears of getting caught up in the vicious circle.
First of all, the fact that you are fearing about getting caught in the cycle means you have already been caught up in it. Now, I say this not to worry you. But notice above the word that I have made bold and italicised… the keyword here is control.
I say this because anxiety cannot be eliminated and if that's your goal, you have set up an impossible task. You need to control it. Which first means you have to accept that you have it - and cannot eliminate it but the key is in controlling your anxiety in which the symptoms caused by it, will also keep under control. That is to say they won't escalate into severe long term symptoms. Like anxiety, you cannot eliminate symptoms of anxiety - only control them. I can use examples: whenever someone has to deliver a speech to a large amount of people, inevitably will they start to become a little anxious; the symptoms caused by this level of anxiety could be the shakes, sweating, puffy face, irritable etc. and this is something that you cannot merely eliminate or avoid - what we do is control them and not let them escalate so we can deliver the speech confidently.
It is the same with any other more severe anxiety related symptoms and more severe anxiety worries; such as cancer and complete numbness of one half of your body (this is an example of a severe anxiety symptom). The key is in controlling it and not letting it escalate any more severe.
I think this realisation is a massive start in controlling your anxiety - first of all.
Secondly, you need to learn how to distinguish between symptoms caused by anxiety, and symptoms caused by other problems. There are a few tricks I have but the tricks and tools I employ is not necessarily going to work for you. You need to do this in order to prevent your thoughts spiralling out of control and instead, you actually start to think logically and rationally. I will share some of the tricks I use to try and distinguish between anxiety related symptoms and other symptoms which may have other underlining conditions.
A log/journal/diary dedicated to your anxiety thoughts and symptoms: what goes into this is first the times and dates you experience worrying thoughts; along with descriptions of those thoughts; along with an anxiety rating from 1-10 (i.e. the stress level); you should also note down symptoms that you experience during those times.
You need to do this in order to reflect on your symptoms and thoughts and analyse them. Not only will you start to pick up on irrational, illogical thoughts you have, but you may also start to pick up on any patterns to your thoughts and symptoms.
The most obvious pattern is a correlation between anxious thoughts and symptoms. You may also notice a correlation between the severity of the anxious thoughts and the severity of the symptoms. That is to say, the more worrying thoughts you have, either you will experience an increase in symptoms, or you will experience an increase in the severity of a particular symptom(s) or both. Note that I used the word "may" earlier. I say this because you may notice no patterns at all in your symptoms and thoughts (although you will most likely find patterns). Your anxiety could be completely random and illogical. The reason for this is because the worrying thoughts and anxiety you are aware of, says nothing about the anxiety that happens at an unconscious level (again, don't let this worry you).
Anxiety happens at an unconscious level also. So imagine the anxiety you are aware of, and then imagine pulling up a whole new blanket revealing a whole new side to your anxiety (yes this is true). So don't worry too much if you don't find patterns. Just keep in mind that anxiety happens at an unconscious level as well.
Other patterns will be the times you experience symptoms. I say this because my anxiety symptoms are almost non-existing in the first few hours of the day. Then after a couple of hours, my symptoms will randomly appear without no apparent cause. Then they may gradually get worse until night. Sometimes when I have stayed up until early hours in the morning, I notice my symptoms go away. But then at that point, because I am thinking about the symptoms, anxiety symptoms has this funny way of only revealing itself when you think about them. So of course I start to experience the symptoms when I have thought about them.
The hardest thing is when new symptoms come. You may learn that yes, you have a twitch, numbness, abdominal pain that is definitely anxiety… but wait… you have just started to get an headache… what do you do now? With me, if my new symptom correlates with my other symptoms, I use this as a cue. So I am basically using my common anxiety symptoms in order to learn whether new symptoms are caused by anxiety. New symptoms I get often come after a few hours into the day (like my other symptoms); they are either triggered or made worse when I think about them (like my other symptoms); and the most obvious one is that they are there accompanied with my other symptoms at the same time. These are all cues in learning whether new symptoms are anxiety related.
When you start to learn this, you start to control them. Because rather than jumping straight into illogical conclusion, and then letting your anxiety take over into the vicious circle, you treat them as if they are apart of your every day living. And you will soon find that they become either less severe or better, they completely go. But remember that you are never free from it. You may just stop thinking about anxiety. And so it doesn't worry you at all. Therefore you will experience the least anxiety symptoms.
Sorry if this is a lot to read. Never think though that you are guaranteed to succeed with these techniques (not to worry you). Note that these are the measures I go through with my anxiety. It does not necessarily mean these will work for you too (but they may).
And also, never ignore symptoms because of course (without trying to worry you too much), you could mistake an anxiety symptom with something that could actually be wrong (now this becomes an anxiety fear itself which I haven't been able to come up with a rational plan yet). But don't let this fear you too much. Remember that it is always better to be safe than sorry. So if you really feel you have to, go seek advice from professional doctors.
Keep me updated on how you feel.