Purpose: To evaluate our surgery for post-gestational rectus abdominis muscle diastasis using slowly absorbable monofilament suture and eight weeks of abdominal binder in terms of recurrence rate, complications, and effect on patients’ physical and cosmetic complaints. Method: In a retrospective cohort study, all 44 patients operated between 2014 and 2020 were invited to a follow-up using ultrasound, clinical examination, and questionnaires regarding symptoms before and after surgery. Results: 89% of invited patients participated, with a median follow-up of 36 months. There was one recurrence caused by severe postoperative nausea and vomiting, which was the most common complication. Most procedures were safe, but two patients experienced Clavien–Dindo grade 3 complications. Patients reported feeling limited or taking precautions after surgery for a median of 8.5 months. Of all included patients, four responded that the operation did not alleviate their primary complaint. The remaining 35 patients (90%) experienced complete or partial alleviation of their primary complaints and would undergo the procedure again if needed. Conclusion: Post-gestational diastasis recti can be associated with a large number of physical symptoms and functional complaints and can safely be operated using a single running plication of the anterior rectus fascia with a slowly absorbable suture, with fair cosmetic results, excellent effect on symptoms, few complications and high levels of patient satisfaction. Future research must determine which symptoms and findings should indicate surgery.