For most units, planning leave is like planning your vacation with a civilian job. You talk with your boss, make sure everything is covered, fill out the forms, get it approved, etc. It's not a big deal. I took a month off to go tour Europe once when I was in the Army.
defecate. 1  to void excrement from the bowels through the anus; have a bowel movement. 2  to become clear of dregs, impurities, etc. 3  to clear of dregs, impurities, etc.; purify; refine.
Anatomy of the anus and rectum. Defecation is the final act of digestion, by which organisms eliminate solid, semisolid, or liquid waste material from the digestive tract via the anus. Humans expel feces with a frequency varying from a few times daily to a few times weekly. Waves of muscular contraction (known as peristalsis) in the walls of the colon move fecal matter through the digestive tract towards the rectum. Undigested food may also be expelled this way, in a process called egestion.