Diastasis Recti Explained: What It Is, How to Check, and Repair vs Exercise

Diastasis recti is a separation of the two vertical rectus abdominis muscles down the midline of the abdomen, where the connective tissue between them stretches and thins. It most often follows pregnancy or a large weight change, leaving a gap and a soft bulge along the centre of the tummy that no amount of core work seems to fix. It is the muscle problem behind many tummy tucks: a full abdominoplasty repairs the separation by stitching the muscle sheath back together¹.

This was the part I understood least before my own surgery. I had assumed my stomach was just “loose”, when in fact the muscles themselves had pulled apart down the middle. Here is what diastasis recti actually is, how to check for it yourself, and the honest difference between what exercise can do and what only repair can do. If you are weighing up surgery overall, start with our guide to the tummy tuck.

What is diastasis recti?

Diastasis recti, also called rectus divarication, is a widening of the gap between the left and right halves of the rectus abdominis, the paired “six-pack” muscles that run vertically from the ribs to the pubic bone. They are joined down the centre by a band of connective tissue called the linea alba. When that band is stretched, the muscles sit further apart and the abdominal wall bulges forward, especially when you sit up or strain.

Pregnancy is the most common cause, because the growing uterus stretches the midline; large weight gain and loss can do the same². It is a structural change in the muscle layer, not simply fat or skin, which is why it behaves differently from the rest of a soft tummy.

How do I check for diastasis recti?

You can screen for diastasis at home with a curl-up test. Lie on your back with your knees bent and feet flat, place two or three fingers flat across your midline just above the belly button, then lift your head and shoulders slightly off the floor as if beginning a sit-up. As the muscles contract, feel for the firm bands on either side and how wide the soft gap between them is.

A gap of more than about two finger-widths that does not firm up when you tense is the usual rule of thumb for a separation worth assessing properly. Repeat the test below the navel as well, because the gap can be wider in one spot than another. A professional assessment by a women’s-health physiotherapist or plastic surgeon, sometimes with ultrasound, gives a precise measurement.

Repair versus exercise: what each can do

Exercise can improve diastasis but cannot close a true separation, and that distinction matters when you are deciding what to do. Targeted core and pelvic-floor rehabilitation strengthens the deep abdominal muscles and can tighten the linea alba, and for mild separations after birth it often narrows the gap meaningfully over months.

What exercise cannot do is pull two muscles back together once the connective tissue is permanently overstretched, and it cannot remove the loose skin that frequently sits over the gap. That is the limit I hit personally: I trained consistently for two years and my core got stronger, but the gap and the overhang stayed exactly where they were. Where a separation is genuine and stable, only a surgical repair restores the muscle wall. We cover this in more detail in muscle repair in a tummy tuck and in does exercise fix loose skin or diastasis.

How a tummy tuck repairs diastasis recti

A full tummy tuck repairs diastasis by stitching the muscle sheath back together down the midline, a technique called plication. After lifting the skin, the surgeon brings the separated rectus muscles in towards the centre and sutures the fascia, recreating a firm, flat abdominal wall, before removing the excess skin and fat above it³.

This muscle repair, more than the skin removal, is why recovery feels like core surgery. The tightened wall is the reason you stand and walk bent forward for roughly the first 1 to 2 weeks, straightening gradually as the repair settles. It is worth understanding before surgery so the early posture does not come as a shock; our tummy tuck recovery guide walks through it week by week.

Diastasis recti versus a hernia

Diastasis recti is a thinning and separation of the midline, whereas a hernia is an actual hole through which tissue can push, so the two are not the same thing. A hernia, such as an umbilical hernia near the belly button, can produce a lump that you can sometimes push back in and that may become painful or trapped, which makes it a medical issue rather than a cosmetic one.

The two can exist together, and a surgeon will check for a hernia before planning any repair, because a hernia may need treating in its own right. Any abdominal bulge that is painful, firm, or growing should be assessed by a doctor rather than assumed to be diastasis. For the wider picture of who benefits from surgery, see am I a candidate for a tummy tuck.