Yes, it is very common for constipation from IBS to cause these urinary symptoms. When stool builds up in your bowel, it can press directly against your bladder, leading to a frequent urge to pee and waking up at night. Since you are already taking Rablet D and Lactifiber, please continue them, but avoid starting new medications without advice, as some bladder medicines can worsen constipation. I gently recommend speaking with your doctor. They can safely evaluate your symptoms and suggest appropriate, bladder-relaxing options that won't interfere with your current regimen.