Dark red lines (like worms) in Yellow poop

Developed alternating yellow stool and yellow diarrhea 2 weeks ago.  Have submitted stool to testing lab but it takes 48 hours to culture, and then get results.

Now I have dark yellow stool, with what looks like red lines in it, almost like worms.

Does anyone have any ideas.  Also a dull pain in my lower left abdomin (abdomen) area.  Have been to the dr, just having to sit thru the weekend without getting the results is stressful.  Please help.

[OmahaArmyMom]

Did you ever get an answer?  I recently have had he same symptoms.  Feel OK other than stool color, mild IBS symptoms and back pain.  Came out of no where.