Can someone please explain to me why it's not recommended to drink with a straw??

When drinking through a straw your sipping in air as well as the drink u are intakeing and that air will get trapped into your stomach as gas and make u feel really uncomftorable.

I drank with a straw everyday since 2 weeks post-op. It was the only way I could get enough Fluid in and as I'm writing this I'm actually sipping through a straw. Most people don't have any gas issues as a result of using a straw and it helps them significantly with their fluid intake. There isn't a medical reason you can't use a straw, doctors just caution against it in the event you may be one of the people that has abdominal discomfort.

Yup, what they said - it might make you gassy or cause you pain.

I'm one of the ones that can't get enough liquid without it. Plus I have sensitive teeth and tend to gulp more WITHOUT one, so I suck down more air that way than using it, so it's not a rule I've ever followed.