I am 17 and have been pooping a lot of

Patient: Hello! I am 17 years old and have a concern (obviously). For the past 4 or 5 days, I have been pooping a lot of blood. Some days the toilet bowl has much blood in it, other days it is only very visible when I wipe. I am on Nexium 40 mg pills that I take for acid reflux (haven’t taken it in 2 days). I just finished using the restroom and it happened again. What may cause this? Should i go to a doctor?

Symptoms: Pooping blood