Hi, My father is a 71yr old man with Parkinsons disease he has had Parkinsons for 15 years now. About 3 years ago he had a bout of diarrea for about 3 months he had a colonoscopy which come back clear they could not find anything wrong. Since then every now and then he gets a bout of diarrea for a couple of days. Now just recently he has had diarrea for about a week and he now has had a few sharp stomach cramps with it. His Dr has sent him for blood and stoll samples, I am assuming the worst are you able to maybe indicate what this could be expecially since they found nothing 3 years ago?