Need Advise on incomplete stool. Help.

I have incomplete evacuation of stool for past 4+years. In the interim it gradually started and now i have to pressure so much to have the stool come out. I even use my half of finger to have the place cleaned. I have not seen any blood in stool and it is coming normal daily. No loose motions often and don't have any stomach pain as well. I went to see doctors and they gave some powder but that doesn't help my problem is not fibre less it is something i dont know what. I need to assistance in this. Might be some muscle problem or i dont know what it is. What is the diagnosis or test should i go to identify the problem and to treat it. Caz i feel afraid that this might be a problem when i get pregnant in future. Please someone help. Thanks