hi im a 32year old female 5'2 12st on monday the day started with lower back pain and uncomfortable tummy early evening had head pains shivers and a temp tues,wednesday had dyrea tummy pains /cramps blood in stools . thursady went to doctore sent stool sample off and have been taking Erythromycin and co-codamol today iv woke up to my stools being green . (green water with dark green stool) is this change in colour due to the medication ?