This is how a <wait for it> PUBLIC forum works: we discuss what you wrote, not what you didn't write.
If you meant the entire occupation, from 2003-2011, you would obviously not have said "100 days" to "take Iraq".
By the nonsense 'logic' you're now trying to use, the Germans didn't "take France" in 1940, because there was still resistance activity afterwards.
So getting back to your actual point again:
"With the capture of the Tikrit region, the coalition declares that the war in Iraq is effectively over."
https://en.wikipedia.org/wiki/Timeli..._Iraq#April_15
"
Most of the Iraqi military was quickly defeated and the coalition occupied Baghdad on 9 April. Other operations occurred against pockets of the Iraqi Army, including the capture and occupation of Kirkuk on 10 April, and the attack on and capture of Tikrit on 15 April."
https://en.wikipedia.org/wiki/2003_invasion_of_Iraq
"conflict in Iraq that consisted of two phases. The first of these was
a brief, conventionally fought war in March-April 2003 [which]
rapidly defeated Iraqi military and paramilitary forces."
https://www.britannica.com/event/Iraq-War
"In 2003, United States-led coalition forces invaded Iraq, and
the Ba'athist Iraqi regime was deposed less than a month later."
https://en.wikipedia.org/wiki/Ba%27athist_Iraq
Post one credible, non-loony source (ie, not you) claiming the Iraqi military/state that existed in March 2003 held out against US/coalition forces for more than 100 days.