The main purpose of the study is to evaluate the effectiveness and safety of the impedance spectroscopy device prototype in detection of anal sphincter injuries in women in the early postpartum period. The study is prospective. The study group comprises 24 patients; included in it 6-8 weeks after natural delivery. The planned participation of each patient in the study is up to 4 weeks and three visits will take place at that time.

After obtaining written consent, at the screening visit (V0) each patient will undergo a physical examination, blood samples for laboratory tests and stool samples for calprotectin concentration assessment will be collected.

On the second visit (V1), after the final verification of inclusion/exclusion criteria, impedance spectroscopy using tested device will be performed in each patient, the electrical impedance of pelvic floor muscles will be measured and the degree of anal sphincter damage will be evaluated. Full gynecological and proctological examination (including a gynecological speculum, two-handed examination, rectal examination and anoscopy) will be carried out.

On the third visit (V2), two reference diagnostic tests (with evidenced effectiveness and safety), transanal ultrasonography and anorectal manometry, will be conducted. The collected data will be used to select the optimal therapeutic method for each participant individually.

Inclusion Criteria:

• after natural delivery and post-partum period (6-8 weeks after delivery)
• physiological pregnancy
• observed a perianal tear of grade 1-4 in the OASIS classification
• signed informed consent

Exclusion Criteria:

• presence of acute diseases during treatment
• presence of chronic diseases untreated or insufficiently treated (e.g. poorly controlled hypertension),
• presence of diseases, with symptoms of fecal incontinence,
• previous proctological operations,
• the presence of inflammatory bowel diseases in the stage of exacerbation,
• treatment in the last year due to severe, progressive, uncontrolled cardiac, pulmonary, nephrological, infectious or psychiatric disease, which course could affect the patient's risk due to participation in study,
• significant deviations from the norm in a physical examination during V0 visit or laboratory tests taken during the same visit,
• significant disease symptoms so far undiagnosed and reported during the V0 visit
• presence or suspected malignant disease or previous oncological treatment during the last 5 years,
• presence of a cardiac stimulator or cardioverter-defibrillator,
• severe surgery or severe trauma in the last year.