FIrst of all....BREATHE. I know that is easier said than done but you have to remember that this is all going to take some time. Some patients have doctors that move a little faster than others but be prepared for whatever comes your way....with respect to the timing. A day or so here or there, while being nerve wracking, is NOT going to change anything.
Obviously, with the tumor that close to the anus, your husband does not have colon cancer. Now, that being said, your husband COULD have anal cancer OR rectal cancer that is NOT the same as the rectal cancers that almost exclusively you will find on this board. You really have no way of knowing until you see the surgeon and get the results of the pathology report. IF you have rectal adenocarcinoma (what most of us on the board have) then your husband will likely have an appointment to have the CT or MRI, and EUS (Endorectal ultrasound....sometimes referred to as a transrectal ultrasound), blood work and then likely an appointment set up with the radiation oncologist. Obviously, as you can tell, all of this takes some time. Now, IF (notice I said IF) your husband's pathology shows squamous cell cancer, that is most likely classified as anal cancer (and sometimes rectal cancer that is treated entirely differently than rectal adenocarcinoma). Wait until you have the pathology report to know exactly what you are dealing with.
Make sure that your surgeon is board certified in colorectal surgery. You'll find that most general surgeons will tell you that they can perform the necessary surgery and technically they can. When dealing with rectal cancer, the surgery is more difficult than colon cancer surgery due to the tight proximity of the pelvis. Here is the link that you can verify the surgeon at: http://www.abcrs.org/verify-a-physician-2/
Don't let anyone pressure you into thinking that you shouldn't have a second opinion if that's what you want. Taking that extra few days, while personally stressful, isn't going to hurt anything. Take your time to choose the doctors that YOU BOTH feel comfortable with and trust.
As far as staging goes that can't happen until all the tests are done. I know it's difficult to be in limbo but in this case, it's just what has to be.