Flomax and solving constipation

I have been on amitriptyline for 30 years, managing its constipation/dry mouth by diet and chewing gum. Was in a world of excrutiatng prostate pain a few weeks ago, and urinary flow and frequency problems. Family doctor put me on Cipro for 2 weeks, but nothing changed. Then a urologist on rectal exam diagnosed enlarged and inflamed prostate, despite no infection detected in urine or blood tests. Put me on another 4 weeks of strong antibiotic and Flomax. Flomax helps, but drawing more water out of my body caused me severe constipation. I tried stool softeners but finally had to use a combo stool softener/17 mg two nights to have a bowel movement. Urologist nurse said doctor said it was OK to take a laxative every night on Flomax, but this sounds counter to EVERYTHING you read about relying on stimulant laxatives. Pharmacist suggested Murilax but that draws even MORE water out of the body. Does anyone have a solution to the Flomax constipation issue? I already am doing all the exercise, fiber, fruits, vegetables natural things I can.