Childbirth Through Normal Delivery, Heavy Child, Loose Motions, Leaking Through Urine Path, Muscle Weakness. Surgery Done, No Improvement, No Holes In Anus. Treatment?

Hello Dr, My sister gave birth to a Girl child (her second delivery). Baby was 4.5 kg but the doctors took her in NORMAL DELIVERY. My sister accepted for surgery since the baby was too heavy, But they denied and took the baby in normal delivery,here comes the problem.. After delivery after few days my sister noticed that she started getting the motion leaking through her urine path ..she went for a check in the same hospital,they said the muscle is weak so gave some tablets and asked her to do the excercises to strengthen it and she also undergone for one surgery for that muscle- no luck,still she have the same issue .. But those doctors saying they couldn t see any holes in the anus ..(not sure whether they examined properly.. My sister facing lot of problems because of this.. In a day motion leaking for more than 3 times..kindly suggest..