Understanding My Constipation and Bowel Health - #47232

I am working with an Ayurvedic practitioner on my constipation issue and am Vata dosha. It would be helpful to understand how much stool should remain in the colon (specifically the sigmoid colon) daily after morning bowel movement. I take stimulant laxatives and osmotic laxatives at night and am trying to reduce them. They cause my stool to be very watery, and I cannot get it all out of the lower left side of my colon even after 3-4 hours of trying each morning. A detailed description of this phase of digestion would be very helpful as I am very focused on getting all of the watery stool to come out but am unable to each day.