Cucumber water does make you poop if you drink enough of the cucumber water.
However cucumbers themselves contain more fiber and will make you poop faster and poop more than just drinking cucumber water.
Although cucumber water does help to cleanse your colon and detox your body and help promote good kidney health so drinking cucumber water daily or every other day is good for your health and can help keep your bowel movements regular.
The cucumber water will help you stay hydrated and help prevent constipation from occurring.
Cucumber water also provides you with nutrients and helps to prevent diseases such as cancer when you drink the cucumber water regularly.