Talk to Gastroenterologist on Diarrhea And Abdomen Pain

EDIT: I HAVE POSTED ON MARHAM forum but i cannot find my enquiry!!!

Any gastroenterologist here? Ive never experienced this, ive got all my blood work done in August and everything was perfect alhumdulilah. My period was a little irregular few months ago its fine now and theres no issue. Right now its been 4 days i'm having diarrhea, and now since a day it has turned dark/black kind of, it comes along with abdominal cramps and i have to rush to the toilet to release, and i dont even feel it coming out. But its still there. A bit Liquidy texture. Ps: I have NOT been taking any vitamin or iron supplements. It just started achanak se. Attaching the type of stool im having and what a general physician has prescribed me