Why no Caffeine?

Why are the RNY patients told to stay away from caffeine?  I am a sweet tea addict, but have grown to like tea with Spenda instead, but I still feel that I will need my caffiene when I  go back to work next week.  I leave my house at 6am and have an hour commute, work a 10 hr shift and then the commute home... believe me, caffeine is needed.... why is it off limits?

Some surgeons will say never. Others allow it after a period of time.

It's the acid that early out isn't good for a healing pouch. It's also known as having diuretic affects.

I drinks lots of coffee it doesn't bother me. I was instructed to wait 3-6 months for full fledged coffee and did caffeine free early out.

 For me, it wasn't off limits, but some people's plan it is. Maybe it can upset tummy or cause ulcers.

I was told it can cause an ulcer and it makes you dehydrate.

I was never told to stay away from caffeine, BUT we were to limit coffee (along with some other liquids like tomato, V8, and citrus juices) the first few weeks while the pouch was healing because of the acid in them. Once the pouch was mostly healed, we were permitted caffeine.

The diuretic effect of caffeine is minimal, but that is sometimes cited by nutritionists as the reason to avoid caffeine. See the following sites for studies that show that caffeine is NOT a significant diuretic (you can also do a Google search for other studies):

http://www.jacn.org/content/19/5/591.short
http://www.mayoclinic.com/health/caffeinated-drinks/AN01661

(Edited to add: Sorry, it looks like the Mayo Clinic folks took away the links to the other studies that were initially on the link I provided above... But I will leave the link to their site so people can see the general answer because at least it lets folks know that the Mayo Clinic -- a reputable place, LOL -- says caffeine is not a significant diuretic. I hate when sites take links away, but I guess it is better not to have them at all rather than have links that don't work...)

Lora

My guideline was to stay off coffee (regular and decaf) for one month.
I had herbal tea in the morning because I like something hot in the morning.
They did not say anything about caffeine in general...although carbonated beverages are a no-no.
They said that coffee in general is very acidic...and some people do not tolerate it well.

At one month, I started drinking decaf coffee...decaf was my previous norm.
My blood pressure has gone down with losing 60 pounds, so I even have an occasional cup of regular coffee.

We were told it's because caffine is known to stimulate the appetite. 

I was told this by my surgeon, too. But I drink tons and it does not seem to increase mine.

 Wow, so many different response to this.  We were told only decaf in the beginning.  I couldn't even gag down any decaf tea or coffee until about a month ago and I am at 5 months.  Now I have a double espresso every morning and doesn't bother me.  If anything, I never am constipated because it gets my system going.  But I also take a prilosec everyday and do not eat or drink any other acidic products at this point.  
It's whatever our surgeon's protocol says.  I like Lora's surgeons protocol from when she had her surgery 5 years ago because hers seems to be the most logical and normal protocol of all.  Jane 

 i was a major caffiene addict prior to surgery.  we were told to hold off due to ulcers and potential appetite stimulant early out.  i haven't had caffiene since the day before my surgery and i have never felt better.  the detox from it sucked, but it's great to not be beholden to a stimulant anymore