You have Scorpio Ascendant with modern ruler Pluto in the sign of the digestive system. With the sextile to natal Moon one would think that the digestive system would work well. The 'adder in the grass' would seem to be the Moon's conjunction with Neptune in its natural 12th house. This 'weakens' the effect of Scorpio's personal controlling system.....physically as well as emotionally. Moon-Neptune square Jupiter in Aquarius (irregular excesses) and Pluto is inconjunct Jupiter. Moon-Neptune are also
inconjunct (predisposition towards disorder through emotional stress) natal Sun in Aries (ruler MC- position in the world) square Mars, ruler 6th house of self-assessment/physical dis-order or dis-ease, in Cancer in 8th( effect other peoples' value systems). There would appear to be a theme at work there. Do you recognise one?
I am sensing a power theme going on here, or perhaps powerlessness.
Imho, each time you react adversely to transits influencing any points regarding your 'personal control system' it could result in a coinciding malfunction of your whole digestive system. I would include the influence of the calculated point MEAN Black Moon Lilith, which is on 6*Leo in your chart (lack of 9th house recognition and/or of self-identity?), closely squares Moon-Neptune, attributing disassociative tendencies, and has been observed to appear to be more the rule than the exception in its influence regarding the onslaught of physical discomforts.
MEAN BML has been transiting Taurus since late last year. It would have been in aspect with Jupiter in January, Moon and Pluto during February, and with Neptune during March. Did any facts(Taurus) arise of which you were previously not aware, that could have been significant towards any 'flare up' of physical symptoms?
I'll have to read up on BML. I don't know very much about her.
In mid-January I learned that my gastric lap band had almost entirely eroded though my stomach into the interior. The gasteroenterologist was frightened, but I was ecstatically relieved that I didn't have cancer. It was removed 1/23/12 and I spent the next five weeks recovering from the surgery. I was lucky. I had no symptoms other than having trouble swallowing.
Do not forget that Mars was in a long term 8 month transit of Virgo, where it conjoined your natal Pluto, and only recently entered Libra. Said simply, I have witnessed too many people experiencing 'realisation hitting them in the face' (some as a result of those 'hidden facts') in one way or another. The Virgo security has undergone attack from Mars' assertiveness of 'proving yourself'.
March was when we found out how many people were going to be cut from school district. Late April was when I found out I wasn't going to be one of them. I have a lot of seniority, but am a school librarian and librarians are expendable in the minds of many (ignorant) school administrators. Its been fraught with anxiety to say the least.
As already mentioned by Anachiel, IBS is affected by the autonomic nervous system, the rulership of which falls under Uranus as modern ruler Aquarius. The nervous system is ruled by Mercurty of Gemini. Your chart shows an inconjunct aspect between Mercury-Uranus.
Finally, modern medical astrology works from the perspective that emotional unease or that of the psyche can bring on physical disorders. (By coincidence, I read recently that the medical world is beginning to think in a similar fashion regarding onset of symptoms!) You said that your disorder began about 20 years ago. Physical disorders do not arise overnight but have an 'incubation period' within the body. The physical symptom is acknowledgement that the body is out-of-order.
Looking at your progressed planetary positions about 22/3 years ago, can it be coincidence that progr. Sun conjunct Mercury opposed Neptune whilst progr. Moon was conjunct Moon-Neptune-Ascendant and conjunct tr. Pluto, and tr. Neptune in Capricorn opposed natal Mars? Can you recall anything important occuring at the time that may have led to 'an incubation period' occuring ?
This was also about the time, although that may have been around 15 years ago, that my parents finally realized that grandma wasn't quite as nice a person as everyone thought she was.*
I'd always had a good relationship with her until I was around ten or eleven, then I didn't want to be around her as much, but I couldn't articulate why. No one could understand why I didn't want to be around her for long periods of time.
When I was in my thirties she moved in with my parents and started driving my mother crazy to the point where mom was ready to move out. At one point she told my aunt that she "...could end my parents' marriage anytime she wanted to."*Then my uncle and aunt moved her into a retirement community where they lived. She started driving my aunt crazy by calling her twenty and thirty times a day, and expecting my aunt go drop whatever she was doing and come over and "help" her. It turned out that grandma behaved completely differently toward the women in the family when her two boys weren't around. She became manipulative, passive aggressive, and mean - but never when men were around.
I think I had picked up on that subconsciously*as a child but didn't know what it was, therefore, there must have been something wrong with me. It wasn't until years later that I was vindicated. I really loved my grandma, but she had a hidden side to her that was a real piece of work, and when I was little, I was powerless.
BUT, in defense of grandma, her own mother was mean and manipulative. Grandma loved animals her whole life. The only story I've heard about my great grandmother is that she cooked grandma's beloved pet rabbit and served it to her for dinner. Grandma never got over that.
With tr. Pluto positively influencing the Moon, itself, and eventually Neptune, you will hopefully come up with some 'psychological' answers that will help towards relief of the physical symptoms in the future