I don't have constipation. but still find it difficult to pass normal soft bowel movements. i feel incomplete evacuation of stools?

It happens. Sometimes the nerve endings of the rectal vault send confusing signals so you feel residual when there is little there. You can also have weakened emptying if the muscles there have stretched out over time. This happens when you try to hold on too long routinely & the bowel balloons some. Teaching yourself to empty more often & keeping less near the outlet over many months may help.

You could try increasing the fiber in your diet. You may take a fiber laxative like Metamucil and drink enough water daily so that your urine is colorless. For the long term you may try to increase your intake of fiber foods. Consult this site for fiber foods. http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/high-fiber-foods/art-20050948 Wish you good health!