Take magnesium daily. Cheap stuff from walmart is fine. Magnesium deficiency causes constant constipation. Drink water. Without magnesium, i go days without going. It makes things runny at first but after a few months, your system balances and you'll go every day. Magnesium is responsible forever 300 paths in the body. 90% of Americans are deficient. Less saturated fats, starches and dairy....more veggies, fruits and healthy, non irritating grains.
Tree242, part of the mechanism of how a stool is moved forward and out is due to the stretching of the muscles of the large intestine. When a stool is smaller in diameter or very soft, it doesn't expand the muscles - in diameter - and that doesn't initiate a series of actions that causes all the muscles to work together to move the fecal material out. The general idea is to add fiber to the diet to help bulk-up the fecal material and enough water to make sure the fiber stays moist and flexible to stretch the muscles and move things forward.
You may want to consider trying to add fiber (soluble and insoluble) in addition to more fluids and see if it's of help.