What about changing rooms?
Being in a changing room with others can be a hurdle to overcome. As with so many other situations, just thinking through the likely reactions can be a big help. Would you prefer to conceal your pouch? There is no right or wrong choice, so just do what feels most comfortable for you.
However, and especially if you exercise with someone you know, consider if it might be easier in the long run to be open and upfront from the beginning, rather than having to think about it every time you exercise together.
A good plan would be to think your explanation through ahead of time. Perhaps you can simply take the initiative by saying it is your first time in a while - or that you have to take it slow today – as you have had abdominal surgery not too long ago. That is probably all the explanation you need.
This website includes general guidelines. Always follow the instructions by your healthcare provider.