Abdominal wall diastasis is caused by developmental disorder of the rectus abdominis muscle or a defect acquired during lifetime (in women it occurs most commonly after childbirth). The rectus abdominis muscle consists of two symmetrical parallel muscle bundles. In case of diastasis the muscle bundles are located too far from each other. It appears as a ridged midline of the abdomen above the belly button, it is thin-walled when palpated. Surgical treatment is required. The best result is achieved in combination with abdominal plastic surgery.