Hey mama! From what I've heard around, stringy bits in breastfed baby poop are actually pretty normal, especially at 4 months, and if she's feeding well and acting her usual self, it's likely nothing to worry about. A lot of mums I know have seen the same thing, particularly when the consistency changes a bit day-to-day, which honestly happens all the time with exclusively breastfed babies. That said, kung makikita mo na ang dark bits keep showing up or if she develops a rash, becomes uncomfortable, or kung medyo off ka lang sa feeling mo, definitely worth a quick check-in with your pedia just para peace of mind, better safe than sorry, diba? Trust your gut as a mom, kasi ikaw ang closest observer niya!