Colorectal problem. Intussusception?

I had subtotal Colectomy(slow transit constipation)I had the problems-Rectoanal intussusception,mucosal prolapse and solitary rectal ulcer syndrome(SRUS) before surgery..After surgery stool is getting stuck in the rectum(once I had put finger while passing stool where i felt that my rectum is being obstructed by something and was unable to take out the stool by finger also..Since then I never tried doing it...My question is can slow colon movement create such problem even after subtotal colectomy(ascending to sigmoid anastomosis) can this much part of colon cause such problem(problem means incomplete evacuation)If it is so then why am i feeling obstruction in rectum?Are my problems due to slow colon transit or recto anal intussusception?Kindly help me to solve this problem..Plz...