About four months ago i started having the same (or very similar) urinary issues you are having. . .was getting quite annoying. Went to the urologist and she did some tests and says I have spastic bladder - essentially, the signals of when it is full get confused. . .so, when there is very little in there it thinks it is full and/or when full it doesn't always send the right signal.

She prescribed Sanctura RX and it has worked great. Most of the time my bladder functions like it used and when it doesn't it is much more milder than before.

I went thru it w/ chronic constipation. Finally had my colon removed last year, so I know what a pain bowel problems can be.

I would suggest you take a stool softener and see if that helps move things thru better for you. Try this first since it's a more natural product and not hard on your body like a laxative is.

I have paralysis of B&B and take Valium 10 mg 3 x day for urinary retention and when that does not work I have to self cath! I have tried it all with # 2 and I found a miracle food that works for me, instead of going every 5-7 days I am now going daily, its called Activia and its like a 3 oz smoothie and it tastes good too! I drink one a day and thats all it takes! I did miralax, reglan, all the OTC stuff, and all the RX stuff and this is first time anything worked for me!
Good luck!