( Notice the skin about the belly button getting smoother)
After you have had a baby, not only do you have to work out and get your abs tight again, but the skin on the stomach itself has broken down the collagen during the pregnancy. As we age, the collagen continues to break down leaving the skin looking altered and may not go back to its former glory.
I will tell you that my own skin, while I was blessed with no stretch marks due to my heritage, I do now have altered collagen around my belly button. I have been testing a product called Regenemax, which is largely made of choline which is a macronutrient that aids in connective tissue regeneration which also includes our stomachs, facial wrinkles and breasts. So what I am really saying is that this is my vanity supplement and this is what I am taking and trying to get my body back.
I am going to do it and show you a picture, because I started this as an experiment on my abs specifically and I am still testing it. So far, it appears to be working on my abs, but not on the eye bags yet unfortunately. So here is my abdominal photo and the product I am testing which is pharmaceutical grade Regenemax (choline).