5-7 pound weight gain by end of every day

So I didn't have a scale for most of my weight loss. But now I just got one an I weigh my self a lot at first an noticed that I would have gained 5-7 by the end of the night. Then go back down ever morning. Is that normal? I don't ever remember my body doing that before surgery. Does it happen to any of you? I just want to make shore there is nothing wrong with me. I think it might be just weight from food in my intestine cause it does not adsorb like before surgery. I don't really know. Any thoughts????

 I rarely get on the scale unless I notice that my pants feel tighter, so I wouldn't know.   I do notice that I retain far more water now as a post-op, and apparently that's not that uncommon for us, as (and others explain this better than I do) but our shrunken fat cells act as little sponges and fill up with fluid.   As long as you are the same weight in the morning, I wouldn't worry about it.   

I haven't had surgery yet but I think I'll hide my scale in a cupboard that I can't reach easily before I do. I don't want to become obsessed w/my scale. I use to weigh myself only in the morning after peeing to see myself at the lowest weight possible. I'd avoid doing it more than once a day because of the way our weight fluctuates during the course of the day. That happens to people pre-op also. 

 You are my kinda gal.    Dr. Kemmeter told me at my two week post-op check-up, "Now, I have some important advice for you.   Give your scale away to someone you don't like very well."    I have a HUGE scale phobia brought on my years of very emotionally abusive behavior by my parents.  I only weighed in once a month for the first eight months post-op.

 Yes it's normal. Especially if you are keeping yourself well hydrated. A pint of water (16 oz) weighs a pound. 

The large part of your weight "gain" over a day is water, but also you are likely carrying around food mass still in your stomach and intestines.

It would be nearly impossible to gain 7lbs of fat in 12 hours and then lose it all over night.

Heck, I went to the fair and "gained" 11lbs that day...that was all gone by morning.  

Does your belly get bigger to got with the gain?

Because I get both of those signs as a HINT that there's a war going on in my gut...usually it means I ate too many carbs or I've been on antibiotics or some otherthting that causes a gut war.

Wait a minute... antibiotics cause weight gain?

Not for me...but they DO cause gas and bloating while the war between the good and bad is going on in my gut.  Some people also get diarrhea.  Many take probiotics or extra probiotics to prevent this problem.

 I think it probably is the water & coffee intake. I drink 3-4 bottles of water an 3 cups off coffee every day. An a large glass of milk. Thanks for your input's  :  )