External anal sphincter repair by the overlapping method in obstetric anal sphincter injury syndrome

Introduction
Obstetric anal sphincter injuries (OASIS) are complications that occur during vaginal delivery. These injuries, also called third-and fourth-degree perineal tears, include the anal sphincter complex and, in more serious cases, the anal mucosa. OASIS contributes to short-term morbidities such as wound site problems and perineal pain. It is also the leading risk factor for upcoming loss of bowel control in women.
Case
Our study aimed to present the diagnosis and treatment process of our 36-year-old patient who had her first and second birth vaginally and developed OASIS in her third birth. After third vaginal delivery, an external sphincter injury was noticed, and surgery was performed at that time, which was not successful. About 9 months have been waited for surgical treatment to be applied to eliminate the problem. In the process, the patient's quality of life was negatively affected as a result of the procedure, as she changed underwear five times a day and used diapers.
Conclusion
For OASIS treatment, it is necessary to use the proper diagnostic methods, ensure appropriate conditions and the teamwork is required. Every vaginal delivery comes with a chance of perineal injury, and all measures should be taken to prevent it. Once it is detected, it is recommended to be treated surgically as soon as possible with the appropriate technique. If the conditions are not suitable, it should be postponed to a suitable time. It is adventegous to avoid the complications that may occur if the surgery is conducted by a surgeon with significant experience in the field.