25 yr male, no notable medical history. For the past month, though only occurring maybe once a week, I've been experiencing slight/very dull burning/pressure/gas in lower left stomach, which is somewhat bloated. I have a high-stress job, and for the past month I've increased my drinking of coffee to 2-3 a day (from 1 cup per day), plus roughly two glasses of Kombucha (non-homeade) a day. This past weekend, I noticed the sensation in my lower stomach a bit more stronger, though on a pain scale of 1-10, I'd give it a 2 - it's just annoying and discomforting. It feels like a combination of gas and slight pressure in my lower stomach, and a little bit into the groin. It's lasted for a few days now, mainly flaring up after I eat lunch though the night, though it seems to be gone when I wake. I've tried to remedy it with a few doses of Pepto Bismol, but it didn't seem to work. Couldn't really pass gas, and just now I noticed that my stool is basically black, though soft - almost intestine-shaped, and not tarry/runny. Know Pepto can cause it to be black, but the sensation as described is still present. Haven't felt this really before (prior to a month ago), as when I have gas, it's usually not this low in the body.
Any idea what this might be?
I will be setting an appt with a doctor, but just wanted to get a 2nd opinion, hopefully in the interim.