** Thanks for contacting HCM with your health concern 1. Although black spots in stool indicates bleeding from the gut but could be due to other cause like: . taking iron in diet [make sure digestive enzyme is free from it] since it also causes diarrhea [soft stool] . since taking probiotics which contains dead yeast/bacteria thus could be their presence in the stool . or from seeds of fruits you have eaten [like banana], beet,undercooked red meat, licorice,coffee,blueberries,blackberries,pepper. 2. but since you do have upset stomach thus one has to investigate fully, so consult a Medicine Specialist or Gastroenterologist for the same to exclude inflammatory disorder of digestive tract or due to parasites in stomach 3. If black specks are accompanied by foul smell,cramps,loss of appetite, pain one should be properly screened and consult a Doctor.