Sounds like you are a healthy eater, I am sure the stool fibres are normal (some of the pics you posted were part from a reference photo right?) I am going to assume you have allergies to a few things, and it may be that your digestion is becoming sensitive to something.
Lactose intolerance means you are deplete of beta-galactosidase, which in my opinion is a result of Antibiotic use. I am also lactose intolerant.It can cause a large number of downstream digestive problems .
Not sure what your symptom range is, but I assume you have experienced a change in digestion. The itch bum means you are producing mucus, and you have some minor intestinal inflammation. This could be from a PH imbalance due to an autoimmune or allergy, or from a change in microbial environment, including non-symbionts.
Can you list the symptoms ranging from the most sever to the least?