What Causes Abdominal Cramps And Diarrhea After Taking Normaocol Granules Post Colonoscopy?

After a colonoscopy on Tuesday last I took normacol granules as prescribed. However while still slightly sedated when being told of the the prescribed granules I heard night time and thought that the granules were to be taken at night time which of course is exactly what you are not supposed to do. I stupidly, without reasoning the instructions, took the granules before going to bed and again the next night. The second night I felt awful cramps and of course had diarrhoea the next morning. I haven't taken the granules since because I gave myself such a scare. Could I have done some harm?