Diastasis & Lower Back Pain.
Your core works as a single unit. The abdominal muscles, diaphragm, pelvic floor, back etc all work as 1.
Imagine a can of Coke. If you try and squeeze the can without pulling the tab, you can't crush the it. The system is pressurised and STRONG, everything working together. If you break the tab seal, just a tiny bit, it loses pressure and you can eventually crush it.
Your Core is also a pressurised system. Stand, sit, bend, the pressure remains the same. With a Diastasis, the abdominal muscles split weakening your core and this can be translated into a number of problems, back pain being one of them.
Here is some great feedback from a Diastasis client. When you have children, you spend a lot of time bending and lifting, having a strong core is important. But at the end of the day, you don't want to suffer with a sore back. Working on one, works on the other.