Black streak in stool plus burning abdominal region?

I'm a 21-year-old female who has had digestive problems for forever. I'd often get upset stomachs, burning pains in my stomach, and acid reflux and still do. I took several rounds of Antibiotics as a child for chronic ear infections.

I was diagnosed with candida overgrowth about a year ago and have had consistent yeast infections since (except on my period), but now I wonder if it's something else too at this point. I only have daily or almost daily stools (sometimes even 2 a week) when I'm on my period, which I am on right now. Otherwise, it's more like 2-3 stools a week.

Yesterday and today I experienced burning in my stomach along with slight nausea, increased gas (very foul-smelling), lack of hunger, excess mouthwatering (usually happens when I skip a meal/eat late), shakiness, and weird stools. Also, I'm on my period, so I have had a lot of bowel movements since Thursday. The first one had a cream/white tip. I also urinated very cloudy with a few white "fibers" in it. Then I had the stool pictured below. I was nervous because one of the stools had a long, black streak. You can see it on the left in the picture below. I also have cream dots/specks/crumbs (I usually only get these when my digestion is "acting up"); it worries me as these stools are accompanied by other odd symptoms. I seem to find relief after going #2 when I have these pains but not completely.

https://www.curezone.org/ig/i.asp?i=96835

Does anyone know what's up with this? I can't seem to find answers; I have a range of digestive problems. I had to stop taking probiotics and my antifungals because of my pain and weird stools. I'm not seeing my doctor until Friday.

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