A chart listing colors of stools and the possible associated conditions is available on MedicineNet.com. The site also provides explanations concerning changes in stool color and advice about when to see a doctor.
While most stool color variations are a result of changes in the diet, some color changes indicate certain conditions, such as gallbladder, celiac, Crohn's or diverticular disease. Changes also may result from cystic fibrosis, ulcerative colitis, tumors or hemorrhoids. Individuals should always consult a doctor in the case of black tarry stools or bloody stools, as they may indicate bleeding from the colon, small intestine or stomach and constitute a medical emergency.