After colectomy, till how many days is white mucus released from anus? After how many days is the temporary pouch for stool collection removed?

Indefinite, depends. The lining of the colon and rectum always makes mucus but it gets hidden in the stool. Without stool passing through the rectum the mucus is more apparent. Timing for closing the colostomy depends on the conditions that lead to surgery and the degree of difficulty of the surgery. Generally 3-6 months in most patients.