I'd actually be wary of using supplements or medications as our bodies (particularly kids) can become dependent on them really easily and then it's really hard to get things on track without them. I would see this as a last resort, and only ever for a very short period of time.

What you describe could be within the normal range, or might be related to something going on like a food allergy or intolerance. Was there a particular reason for chaning to A2 and has it made a difference? If you suspect a dairy issue and A2 hasn't made a difference, it could be the other protein in dairy (the one that's in A2 milk) that is the culprit. Or it could be a different sensitivity altogether, or not a problem at all. The only way to rule out food sensitivity is to do a full elimination diet and then challenge for one element at a time. It's time consuming and hard work but it does give you the answers. If you suspect dairy you could start by cutting that out totally (including all foods with milk solids, there are a lot) - a dietician is a good idea as they can help with a diet plan that meets all the nutrition needs.

Does your DS drink lots of water? Does he have accidents often? If this is something that is not in the normal range, there are other reasons why kids can have troubles - lack of muscle control, lack of sensation of needing to go etc. It really comes down to how much of a problem it is. If it is a problem than resolving it before it affects him at school is a good idea. Perhaps seeing an OT that specialises in toileting could help. They will give you a good idea of whether this is just a version of normal, or something that needs to be looked into further, and can help you with strategies too.

All the best with it.