Read all you can - the link below will get you started on Bowel Cleansing options.
I don't know much about colema's or enemas - but people swear by them!
1. Drink 2 litres of WARM water daily - this is a must and will get you hydrated.
2. Read 'Journey to the Center of the Colon' at the Doctor Within site within link below.
3. Start bowel cleansing! You'll probably want to Liver Flush too!