Ab separation, known medically as diastasis recti, is a condition where the two sides of your abdominal muscles pull apart along the midline of your belly. The gap typically measures more than about 2 centimeters (roughly two finger widths) and can cause a visible bulge, back pain, and weakened core stability. It’s most common during and after pregnancy, but it can affect anyone.
What Happens Inside Your Abdomen
Your “six-pack” muscles (the rectus abdominis) run vertically on either side of your belly, connected in the center by a strip of connective tissue called the linea alba. Think of it like the seam running down the middle of a zipper. When that connective tissue stretches and thins, the two muscle columns move apart, leaving a gap.
This gap changes how your core functions. The abdominal wall works like a pressurized canister: your deep core muscles, pelvic floor, and diaphragm all coordinate to stabilize your spine and support everyday movements like lifting, bending, and even standing upright. When the front wall of that canister is compromised, the whole system loses tension. That’s why ab separation causes problems well beyond appearance.
Causes and Risk Factors
Pregnancy is the most common cause. As the uterus expands, it pushes the abdominal muscles outward, and hormonal changes soften the connective tissue to accommodate growth. In some cases, an anteriorly positioned baby concentrates pulling forces on the linea alba rather than spreading them evenly across the abdominal wall, which increases the likelihood of separation.
But pregnancy isn’t the only path to diastasis recti. Rapid weight gain or obesity places sustained outward pressure on the abdominal wall. Repeatedly straining during heavy lifting, chronic coughing, or intense abdominal exercises can also contribute. Men and people who have never been pregnant can develop it, though it’s far less studied in those populations.
Signs You Might Notice
The most recognizable sign is a bulge or “pooch” that sticks out above or below your belly button, especially when you strain. Many people notice it persists even after losing weight gained during pregnancy. Other common signs include:
- Coning or doming: a ridge that pops up along your midline when you contract your abs, lean back in a chair, or do a sit-up
- Softness around the belly button: a jelly-like feeling when you press into the center of your abdomen
- Low back pain: one of the most frequently reported functional problems, driven by the loss of core support
- Difficulty with everyday tasks: lifting objects, walking long distances, or maintaining good posture can feel harder than expected
If separation is severe or left unaddressed, complications can develop over time, including umbilical hernia, urinary leakage, constipation, and pelvic or hip pain. The progressive laxity of the midline tissue makes hernias particularly common, and repairing a hernia without addressing the underlying diastasis often leads to recurrence.
How to Check Yourself at Home
You can do a simple self-test. Lie on your back with your knees bent and feet flat on the floor. Lift your head and shoulders slightly, as if starting a crunch. Place two fingers just above your belly button and press gently into the midline. Repeat at the belly button and just below it. If you feel a gap wider than two finger widths, or if your fingers sink noticeably into the space between the muscles, you likely have diastasis recti.
Keep in mind that two finger widths is a rough guideline. That measurement equals about 3 centimeters, though it varies depending on your hand size. Ultrasound imaging is more precise: clinically, a gap wider than about 22 millimeters above the belly button or wider than 16 millimeters below it generally confirms the diagnosis. But the finger-width test gives you a reasonable starting point before seeking professional evaluation.
How It Affects Daily Life
Back pain is the functional problem most strongly associated with ab separation. Without proper tension across the front of your core, your spine loses a key source of support, and your lower back muscles compensate by overworking. Poor posture follows naturally. Studies evaluating people before surgical repair found significantly reduced trunk endurance: in one assessment, participants could hold a stability position for only about 40 seconds on average, compared to 56 seconds after repair.
The effects extend beyond the back. Your core muscles, pelvic floor, and diaphragm work as a team. When one part of that system weakens, others follow. Urinary incontinence, pelvic pain, and even changes in breathing patterns have all been documented alongside diastasis recti. These aren’t inevitable outcomes, but they’re common enough to take seriously.
Rehabilitation and Exercise
The first line of treatment is targeted rehabilitation, not generic ab workouts. Effective programs focus on retraining the deep core muscles that stabilize the abdominal wall from the inside. This typically includes pelvic floor exercises, deep abdominal engagement (contracting the deepest layer of your core rather than the surface muscles), and diaphragmatic breathing techniques that coordinate the core and pelvic floor to rebuild intra-abdominal pressure.
Diaphragmatic rehabilitation, in particular, gets strong support from clinicians. The diaphragm works in sync with the pelvic floor and deep abdominals to create spinal stability, and learning to use all three together is the foundation of recovery. Yoga and suspension training have also shown promise, though the evidence base for those approaches is still growing.
Equally important is knowing what to avoid. Any exercise that causes your abdomen to bulge, cone, or dome is pushing pressure into the weakened tissue and can make the separation worse. Traditional crunches, sit-ups, and many front-loaded exercises fall into this category. The visual cue is straightforward: if you see a ridge forming along your midline during a movement, stop.
When Surgery Becomes an Option
Most people improve with consistent rehabilitative exercise, but surgery is considered when symptoms persist despite physical therapy or when the separation is severe enough to cause ongoing functional problems. The decision is based on a combination of symptoms (typically pain that worsens with movement) and physical findings like visible abdominal wall distortion during muscle contraction.
Surgical repair brings the separated muscles back together and tightens the stretched connective tissue. It’s often performed alongside hernia repair when both conditions are present, since fixing a hernia alone in the context of diastasis has a high recurrence rate due to the poor quality of the surrounding tissue. After surgery, studies show meaningful improvements in back pain, posture, core stability, and trunk endurance.