Hi there on Sunday I had been out for a meal, I felt fine afterwards. However by 9 pm I started to feel very unwell I went upstairs to the bathroom and was violently sick after lying down I felt a little better however once I stood up I felt very sick again, this nausea continued for approximately 2 hours. I then started to suffer diarrhoea during this time I also had stomach pains and cramps these continued throughout the night. After a few hours sleep I felt very drained when I awoke, during the day I felt very lethargic and had to lie down frequently as I didn't feel I had any energy I also had chills and a temperature can you please diagnose the cause of this unpleasant illness