Digestive Tract Health and Healing

Along with fibromyalgia, it is not uncommon that digestive tract problems are also experienced by these affected persons. I'm also included. My own digestion problems started at age 12.
The digestive tract is also where the primary amount of Serotonin (a chemical that aids in relaxation) is produced.
Many antidepressant drugs help with serotonin in the body. For those taking them to reduce pain, this serotonin aids to bring relaxation by reducing muscle tension and stimulating rest/sleep.
So the next question, how can we help our digestive tract absorb nutrients appropriately and produce the essential chemicals, enzymes and hormones we need for good health.
This is not easily answered, as we are all "fearfully and wonderfully made" individuals. What works for one person may or may not help the next person.
I'll tell you what I've found out for myself.
First, identifying that dairy products caused a great deal of the abdominal discomfort I experienced (including several Emergency Room visits for extreme unremitting abdominal pain). Just a side note-I've had multiple allergy tests, but there was never any food allergies or other allergies identified. These sensitivities I figured out on my own with trial and error.
Second, animal meats/fats (all types  including fish) even lean cuts would often cause gallbladder attacks. However, I have no gallstones. One doctor said I had what he called "gallbladder colic"?
Third, deciding that the vegan dietary lifestyle was worthwhile to try.
It has been 4 months now, several in transition to retrain my taste buds.
Results, overall reduced joint pain and swelling, significantly fewer episodes of even a slight abdominal discomfort. Sleep can be still somewhat of a problem. A skin rash on my lower leg is healing finally-it has been there for two years-doctors couldn't tell me what it was. I suspect that the increased allergies I developed-sinus headaches/infections, the rash were Candida influenced due to the lifelong amounts of antibiotics I've taken. Extreme fatigue has reduced moderately.
Next I feel well enough to try to get back in the pool to exercise.
I started taking powder probiotics twice daily (to reintroduce appropriate/healthy bacteria to my gut), morning and night. Also, 2 oz of Aloe Vera juice morning and night . I take Kolinead 2 capsules every morning before breakfast for fibre and bowel health. I also include multivitamins, Vitamin D, Calcium and Co Q10.
I still need to take the medication for Serotonin, but my dosage have decreased.
I take fewer pain pills daily.
I believe that my digestive tract is slowly healing, and is beginning to produce the serotonin in the gut as it was designed to do. It takes time to undo 40 years of digestive tract problems.
In order to also help with healing I added soy protein powder to at least 1 smoothie daily. This protein is easily absorbed and will aid to improve my immune system and cellular healing.
I'm definitely not where I wan't to be in regards to my health, but I know that I'm headed in the right direction. For me, the vegan dietary lifestyle has been the best choice for me.