I (M37) just had “coffee grounds” stool, but no other symptoms, and I already have a colonoscopy/endoscopy in 13 days.

Hello! I’m a 37/male, around 390lbs, 5’10. I have a colonoscopy/endoscopy scheduled for July 16th. The reason is/was some bright red blood on toilet paper (which has resolved since I scheduled this procedure in January) and extreme GERD.

I’ve had three endos before. Each time they had to dilate my esophagus due to stricture. My throat is always on fire. I cough. I burp nonstop. I’ve also had a colonoscopy in 2017 due to excessive bright red blood in stool. They found nothing wrong in 2017. None of my endos ever turned up anything crazy beyond strictures and scarring. My last one was about 8 years ago.

I started dieting on July 1st. Nothing extreme. I just decided to give up fast food and junk like candy. I still drink Diet Coke pretty heavily. Since the 1st the only significant eating I’ve done was a salad, some steak, cheese, a protein bar, and some cotton candy grapes. I’ve also been drinking a lot more water.

Yesterday I had diarrhea, which I chalked up to my gut adjusting to new eating. The color was normal. Today, I had it again, but this time the stool was black and had the classic “coffee grounds” appearance they tell you to watch for. Naturally I’m concerned, however, I’m not experiencing any other symptoms. No dizziness. No puking. No weakness. Not anymore short of breath than usual. I also didn’t notice a particularly foul smell, at least not any worse than poop smells normally. I have been experiencing some light burning in a band around my gut for a couple weeks. I chalked it up to GERD as that’s almost always what it is.

Im wondering if this warrants an ER visit. I was going to message my PCP but it’s a holiday weekend and I know he’s not there and won’t be until Monday. Since I have a colonoscopy/endoscopy coming up, and I don’t have any other extreme symptoms, I feel kind of frozen. Obviously if I’m profusely bleeding from the inside that can’t wait 13 days.

Thanks in advance for any advice.