Why does the food change color when you digest?

Are there any tips for eating if you have acid reflux? How many shaves from a Gillette Sensor Excel cartridge? Can beer give you a stomach ache twelve to sixteen hours after drinking it? What is DNC? What fertilization that occurs inside the body? What are four phenotypes of human blood? Can fibroid tumors mimic a pregnancy? What could you have if the back of your head makes you feel dizzy? What were the to main problems caused by valus? Can infants get HIV? What is the difference between placenta previa and a blood clot in the uterus? What is needed for the stomach protein digesting enzymes to become active? What to expect with genetic testing to determine thyroid cancer? What do you mean by positive tuberculosis extensive disease? Ground glass nodules are they found in the early stage of cancer? Lately I've been feeling extremely dizzy and lightheaded when I stand up after laying down even when I try getting up slowly and I eat plenty of healthy food so what could it be? Does backcombing damage hair? What are the causes of bioterrorism? What are the sources of gaseous poisoning? What medical condition was Alice Walker suffering from when The Color Purple was being filmed?