Extending through the perineum and partly or completely disrupting the anal sphincter, this injury is classified as third-degree. The external or internal sphincter may be affected, potentially changing your ability to control stool and gas and requiring prompt assessment after vaginal childbirth.
This overview explains the injury, warning signs, diagnosis, repair, recovery, and birth-planning questions you may need to discuss with your care team after delivery.
How a Third-Degree Perineal Tear Develops
The perineum is the tissue between your vaginal opening and anus. During vaginal childbirth, the baby’s head and body can place substantial pressure on this area, stretching the skin, muscle, and deeper tissues that support pelvic floor function.
Most birth tears remain limited to skin and superficial tissue, but a deeper injury can reach the anal sphincter. This complex injury falls under obstetric anal sphincter injury, commonly abbreviated as OASI.
| Structure | Role and Possible Involvement |
|---|---|
| Perineal skin | Forms the outer tissue at the vaginal opening and usually tears first. |
| Perineal muscle | Supports the vaginal opening and contributes to pelvic floor support. |
| External anal sphincter | Helps maintain conscious control over stool and gas. |
| Internal anal sphincter | Supports resting closure inside the anus and may also be disrupted. |
The external anal sphincter is the voluntary muscle used when you consciously hold gas or stool. The deeper internal anal sphincter supports closure at rest, so injury to either muscle can change continence in different ways.
A fourth-degree tear extends beyond a third-degree injury and reaches through the rectal lining into the bowel. This deeper tissue involvement changes the repair and monitoring needed after childbirth, particularly when infection or bowel leakage occurs.
How the Injury Differs From Other Perineal Tears
Depth provides the first comparison, but the degree of sphincter involvement determines the likely effect on bowel control. A superficial tear can be extremely painful, while a deeper injury may produce few visible symptoms, so your pain level does not establish the tear’s severity.
| Classification | Tissues Involved |
|---|---|
| Degree one | Perineal skin only, without deeper muscle involvement. |
| Degree two | Skin and perineal muscle, but not the anal sphincter. |
| Degree three | Skin, perineal muscle, and part or all of the anal sphincter. |
| Degree four | A third-degree tear plus the rectal lining. |
More precise subcategories describe the pattern of disruption. A 3A tear involves some external sphincter damage, 3B involves more of that muscle, and 3C includes complete external sphincter disruption with some internal sphincter involvement.
Your care team should explain whether either sphincter was affected and how the classification was determined. That detail helps guide assessment of wound healing, anal pressure, bowel control, pelvic floor function, and symptoms that emerge weeks or months later.
Ask your discharge team to explain the classification in plain language, including whether the external sphincter, internal sphincter, or rectal lining was involved.
Symptoms to Recognize After Vaginal Childbirth
Loss of control, difficult bowel emptying, and wound changes deserve attention because they may indicate more than routine perineal soreness. Gas leakage is not always alarming after delivery, especially when your stomach has been empty, but persistent loss of stool or progressive wound changes require evaluation.
- Bowel control changes: You release gas or stool unintentionally, especially during movement or when you exert pressure.
- Perineal pain: Your wound hurts, feels tender, or becomes increasingly swollen during the first days after delivery.
- Excess bleeding: Bright red bleeding continues beyond the expected pattern of lochia after childbirth.
- Difficult evacuation: Opening your bowels is painful, delayed, or requires substantial straining.
- Possible infection: Worsening pain, spreading redness, fever, pus-like drainage, or a strong odor develops.
- Wound separation: A gap opens, the edges pull apart, or tissue appears to change over time.
- Intimacy discomfort: Penetration or contact near the repaired area causes pain, pulling, or irritation.
You should report symptoms even when the outside of the perineum looks small. Internal sphincter injury may not create an obvious external wound, yet your experience of leakage or difficulty emptying your bowels remains clinically relevant.
Recognizing these sometimes subtle symptoms is especially important when modifiable birth or medical factors may have contributed.
Factors That Can Increase the Risk
Deeper tearing usually develops when several pressures act on the same perineal tissues. Your pelvic anatomy, the baby’s head and shoulder dimensions, fetal position, birth position, and duration of labor can interact, so no single factor determines your risk by itself.
- Instrument-assisted birth: Forceps or vacuum assistance can alter pressure and traction across the perineum.
- Episiotomy: A surgical cut in the perineum can widen the opening under certain clinical circumstances.
- Large fetal size: A larger head or shoulders can increase stretching as the baby passes through the birth canal.
- Prolonged labor: Extended pushing may tire the tissue and reduce its capacity to stretch evenly.
- Forceps placement: The instrument’s shape and position can concentrate pressure in a smaller perineal area.
- Uncertain fetal position: An unusual head position can direct force across vulnerable tissue during descent.
Your risk assessment depends on the combined clinical picture rather than one detail. An episiotomy, an instrument-assisted birth, or a difficult labor may affect tissue management, but your care team must assess the actual delivery and injury rather than rely on the method alone.
Because risk factors alone cannot reveal the extent of injury, diagnosis and repair planning depend on a careful examination of the tear.
Seek prompt medical review for uncontrolled stool or gas loss, heavy bleeding, worsening pain, fever, pus-like drainage, or a rapidly opening wound.
How Clinicians Diagnose and Repair the Injury
Prompt examination after delivery allows your clinician to identify the wound’s depth and estimate its effect on anal function. The assessment includes the perineum, anal opening, sphincter contraction, bleeding, swelling, and nearby birth injuries.
An endoanal ultrasound can help visualize the external and internal sphincters and identify defects or separation. A rectal examination or anorectal manometry may assess pressure or function when symptoms suggest persistent leakage, although imaging does not replace your symptom history.
Repair Process and Immediate Care
Most third-degree injuries are repaired soon after vaginal childbirth while you receive appropriate anesthesia. The clinician removes damaged tissue as needed, aligns the separated sphincter edges, and closes the wound in layers while addressing associated tears or bleeding.
After closure, your care team protects the wound, manages pain according to your medical needs, and helps you begin safe bowel care. Immediate repair restores tissue alignment, but it does not guarantee that every symptom of pelvic floor dysfunction will resolve without later treatment.
Your operative plan depends on tear size, sphincter involvement, symptoms, other birth injuries, and overall health. For a complex injury, a clinician experienced in pelvic floor medicine, colorectal care, or perineal reconstruction can explain the repair and appropriate follow-up.
That specialist follow-up establishes the baseline for tracking healing, bowel function, and pelvic floor recovery over subsequent months.
What Recovery and Pelvic Floor Rehabilitation Involve
Tissue comfort and functional recovery follow different timelines after a sphincter injury. Wound tenderness may improve over several weeks, while bowel control, anal pressure, and pelvic floor coordination can take longer, particularly when rehabilitation is needed.
- Protect the wound: Follow your discharge instructions for cleaning, bathing, movement, and perineal care.
- Support bowel emptying: Ask your clinician about a bowel plan that reduces straining and supports regular stool passage.
- Increase activity gradually: Advance walking and daily tasks according to your comfort and any new leakage or pressure.
- Track pelvic symptoms: Record heaviness, urgency, leakage, pain, and changes that occur during exertion.
- Begin individualized therapy: A pelvic floor therapist can assess your muscle coordination, strength, and pressure support.
- Reassess persistent changes: Ongoing pain, leakage, or pressure deserves renewed evaluation rather than passive waiting.
Your rehabilitation plan may include breathing, muscle coordination, strength training, and techniques for managing everyday pressure. Strengthening without proper coordination can worsen symptoms in some patients, making individualized assessment more useful than repeating self-directed exercises.
Bowel management may involve food and fluid choices, scheduled toilet routines, stool-consistency support, and specialist input when control remains difficult. A diary recording leakage, stool form, urgency, pain, and pelvic pressure can reveal a pattern that guides treatment.
You may experience temporary setbacks because constipation, infection, increased activity, or pelvic floor tension can change symptoms from one week to the next. Fluctuation does not necessarily mean the repair has failed, but a persistent or worsening change should not be dismissed.
Long-Term Bowel Function and Future Birth Planning
Long-term effects can range from occasional gas leakage to persistent stool leakage, altered anal pressure, pelvic floor dysfunction, or pain during intimacy. Your outcome depends on the amount of disrupted tissue, repair quality, and whether symptoms continue beyond initial healing.
Your assessment should extend beyond how the wound looks on the surface. You deserve to discuss how leakage or pressure affects your sleep, exercise, work, relationships, and confidence, especially when these changes persist after several weeks of recovery.
Persistent symptoms may require pelvic floor therapy, anorectal testing, or assessment by a colorectal or pelvic medicine specialist. The evaluation should follow your symptoms and examination findings rather than apply the same plan to every repaired injury.
A previous third-degree tear does not determine the method of your next birth by itself. Your clinician should review the prior repair, current bowel control, pelvic floor function, healing, and the circumstances expected during another delivery before you choose a plan.
Contact a healthcare professional when bowel control, pelvic pressure, wound appearance, or intimacy problems persist or worsen after childbirth, and seek individual guidance before selecting another birth method.
Key Takeaways for Your Care Plan
Your strongest next step is to confirm the exact tear classification and report every bowel-control symptom to your care team. The degree of external and internal sphincter involvement gives your clinician the most useful basis for evaluating healing, rehabilitation, and future pregnancy planning.
Prompt repair addresses the immediate structural injury, while follow-up protects your longer-term function. You can support that process by tracking leakage, pain, bowel emptying, and pelvic pressure and by seeking reassessment when any symptom persists or worsens.
FAQ
What is a third-degree tear during childbirth?
Extending through the perineum and partly or fully disrupting the anal sphincter makes this injury a third-degree tear. The external or internal sphincter may be involved, so the injury can affect your ability to control stool or gas.
Which parts of the anus and bowel are affected by a third-degree tear?
That affects the perineal skin, deeper perineal tissue, and part or all of the external anal sphincter. It may also involve the internal anal sphincter, but it does not extend through the rectal lining like a fourth-degree tear.
How is a third-degree tear different from a first- or second-degree tear?
Only the perineal skin is affected in a first-degree tear, while a second-degree tear extends into muscle without damaging the anal sphincter. A third-degree tear reaches part or all of the sphincter, which can alter stool and gas control.
What are the symptoms of a third-degree perineal tear?
Possible symptoms include perineal pain, swelling, bleeding, difficult bowel emptying, gas leakage, and loss of stool control. Your symptoms may appear mild at first, so your clinician should assess the wound along with your bowel habits and sphincter function.
What can increase the risk of a third-degree tear?
Risk can increase with a larger baby, an unusual fetal position, prolonged labor, operative vaginal delivery, and the tissue and pressure patterns present during childbirth. Multiple factors may interact, including perineal anatomy, birth position, instrument use, and episiotomy.
How is a third-degree tear diagnosed and treated?
Your clinician diagnoses the injury by examining the perineum, anal opening, sphincter contraction, and surrounding tissues. Endoanal ultrasound or anorectal manometry may clarify tissue defects or function, and most injuries are repaired surgically soon after delivery.
