Is the only way to fix a 5.5 cm diastasis recti with abdominoplasty?

Hello. I’m 47 years old, fit, active not overweight 5ft 6 and 10stone. I am a physical therapist and have always exercised and been conscious of my post-partum physical health (3 babies). However recently I’ve had abdominal discomfort which has been investigated with US scan. I have a 5.5cm diastasis plus a small umbilical hernia. My doctor suggests surgery (abdominoplasty plus hernia repair). I am reluctant but wondered what the effects of not having this fixed will be in the future. Thank you.