anyone ever done a colon detox before? are my side effects normal?

Hi, I have just started the Dr Natura Colonix cleanse, I only started yesterday and drank the 1 glass of water fibre mix and then drank a cup of the senna tea before I went to bed, then at about 4am I woke up WIDE awake with a faster beating heart, went to the loo a couple of times which was productive and managed to get back to sleep but today I feel seriously wierd.... bit shaky, had a head ache this morning, feel like i'm "buzzing, slight palpitations it feels like" i'm also feeling a bit grogy in general and just not really with it and with a slightly dry mouth
is this normal or have I just reacted really badly to the senna?

: http://alcoholdrugstreatment.info/anyone-ever-done-a-colon-detox-before-are-my-side-effects-normal-2