Hi,
Black colour stools may be due to
1. Eating dark vegetables.
2. Upper GI bleeds.
3. Iron tablets consumption.
4. Antacids which contains Bismuth.
5.
Irritable bowel syndrome.
6. Food intake that contains an additive colour.
So please check it out. Use tablet
Pantoprazole. Avoid spicy food, alcohol consumption,
smoking and caffeine drinks.
White colour spots may be due to candida infection,
pharyngitis etc.
Use salt water gargling thrice a day for five days.
If symptoms not improved please get upper GI
endoscopy and stool examination done for occult blood. Then consult your gastroenterologist, he will examine and treat you accordingly.
Hope I have answered your query. Let me know if I can assist you further.