Can food affect the colour of your stool?

[Santo__0]

  I am a 23 year old male who doesn't drink, smoke etc.
  My question to you is:
     Can food affect the colour of your stool?
  The reason I'm asking this is because I consumed a fair bit of
  black-currant drink (RIBENA) 2 days ago and noticed purply
  coloured stool this afternoon.  Not only this, the stool seems to
  be rather watery.
  (By the way, I used to suffer from Gastric problems a couple of
  years back. Will this have any long term effect on my body? )
  Also, I noticed that my bowel seems to be very watery everytime I
  consumed milk (straight up). It doesn't happen when I mix it with
  coffee.  Does this suggest lactose intolerance?
  I have heard that soy milk is an alternative to cow's milk. Is it
  possible to condition the stomach to take cow's milk instead?
  Should I consult a doctor immediately in this case or should I
  observe what happens the next few days before consulting a
  doctor?
  PS. I consumed cow's milk this morning. Is it possible that the
  condition I prescribed earlier is attributed to lactose intolerance?
  
  Thanks for your attention.
___________________
Dear santo,
What you eat definitely influences your stool output.  For example, people who take PeptoBismol will  have black stool.  Unfortunately, I do not know if black currants will produce the change you describe.  My suggestion is to stop the black currants and see if the stool return to their normal color.  With regard to milk intolerance, add lactaid to yur milk when you drink it straight up.  
This information is provided for educational purposes only.  Always consult your persnal physician for specific medical questions.
HFHSM.D.-rf