Sorry to hear that. Pentasa is certainly the lowest level prescription drugs that can be prescribed. As you go up in drugs, the impact and potential side effects go up (e.g. next step would be something like Imuran, then Humira). Have you gotten any blood tests recently? C-Reactive counts, Sedimentary rate, and White Blood Cell counts can be markers of imflammation or a change in something. Vitamin D will probably be low if you're not absorbing anything in your gut (i.e. frequent diarrehea).
Personally, if you're at 15x a day, I would go find a different GI. Pentasa just treats the inflammation but doesn't go systemically if its a greater problem.
Other thoughts could be bacteria overgrowth, fungus overgrowth (Candida). What did your small bowel say? Start keeping a food/sleep/stress/medication/alcohol diary as well. Do you respond well to Prednisone? Do you suffer from weight loss?
I had a hysterectomy 2 years ago. I've suspected issues with my ovaries since they didnt remove them but I've gone to my gyn and he tells me its the crohns and my crohns dr says I need to go to gyn so I get the run around with it.
Adjusting your diet is essential with Chrohns. If you still have your uterus, you may want to see a doctor about the possibility of Endometriosis causing severe bowel problems. I suffered for 10 years before they properly diagnosed the problem. A total hysterectomy was necessary then, but the symptoms disappeared!