Tenesmus
It is the name given to a very uncomfortable sensation that you still need to go after you have finished using the bathroom. It is commonly reported in cases of intestinal worms, but patients with colon cancer experience this symptom as well. Tenesmus is caused by a very mild pain signal arriving at the brain from the gut. The brain would interpret this as if you were still holding more stools in the rectum. Many patients would describe sitting for a long time in the bathroom because they still feel the need to continue emptying bowels.