You really should read the articles in the library drop down list above that concern knee recovery.
The question to address is what is inhibiting your bend? Is it swelling? In most cases, it's swelling. You must be very aggressive tackling swelling by proper elevation (knee above heart), good icing, for 30 minutes every couple of hours. This is more important than PT at least right now. Make your every day about getting the swelling down. Not only does it inhibit bend, it inhibits healing. So get your leg in the air most of the hours of the day (in other words, as close to 24 hours as possible!)
Another cause of poor bend in rare cases is the ortho didn't put things in right. You can ask your ortho's office to tell you what your extension and flexion were after the knee was installed -- or better yet, obtain the operative notes.
What are you doing in terms of activity every day? Rest is so important, but for active people, it's like a prison sentence. We need to know you are only doing what's necessary every day, e.g. range of motion movements a few minutes twice a day, some walking, but nothing more, really.
In terms of bowel function, Metamucil is king.
Also, it's hard for us to help you without you telling us how much your knees bend. Is it more or less than 90?
How well is your pain managed?