My wife had a surgery on 06/01/14, and her colon was perforated. On 06/02/14 she had a surgery that repaired the perforation. My question she now has some burping and a constant white foamy saliva, and heat burn. Her salivia is constant and she is keeping us both awake at night as the condition continues throughout the day. She uses a box of Kleenex a day She has used Jensneviolet for a condition called thrush to no avail. Should she have an Upper Gastrointestinal Series. Is there test to determine the cause by testnig the saliva?.