Depend on jenis luka dan dalam mana jahitnya, tapi biasanya benang akan dicabut dalam 7-14 hari, doktor akan bagitau timing yang tepat untuk kes awak. Isi baru yang timbul tu normal je kalau dia soft dan tak merah/bengkak, tapi kalo ada signs of infection macam pus, very red, or warm to touch, better check with your doctor terus sebab it could be something yang perlu attention. A few of my mum friends yang ada luka jahit surgically mentioned they were told to keep the area clean and dry, and the redness faded after a few weeks lagi, but setiap orang lain, so best discuss dengan doctor your specific situation!