Thank you for all the info, I really appreciate it.
And just in case you switch back to vegetarian one day, be prepared for heartburn. With a red meat diet, there is a lot more gastric acid around that tends to irritate the stomach lining once you stop eating the meat.
Well, you might experience constipation or digestion issues. I'd recommend that you take a fibre supplement is reintroducing red meat to your diet. Psyllium husks work well for me. Be sure to drink LOTS of water if you take them. They expand internally and help clear out the intestinal tracts.
I would imagine the safest way to reintroduce meat is slowley and with as little fat as possible - start with small amounts of white meat and build up to red meat because the biggest shock will be to your digestive system - meat is harder to digest than most other foods.
here is an interesting website for you where someone else asked the same question
http://ask.metafilter.com/35455/Eating-meat-again