Yes if you drink enough lemon water then the lemon water can make you poop and help you have a bowel movement especially if you're constipated.
The lemon water can help work as a laxative because the lemon water increases the water content in your gut which helps to get your bowels moving and helps softens your stools.
If you're feeling constipated it could be that you're dehydrated and the lemon water can help hydrate your body and help get the bowels moving.
So drinking some lemon water can help relieve the constipation and it also helps to detox your body as well and provide vitamins and nutrients.
Drinking a glass or two of lemon water per day can help improve your health and it's also a nice refreshing healthy drink.