First of all, take a DEEP DEEP breathe! There's nothing that you can do to change things.....right now the best advice I can give you is to try and put the 'what ifs' behind you and look to the future.
Ok, your mom has a mass in her rectum which is, based on the doctor's best guess....likely cancer. While the biopsy is the definitive answer, doctors can usually tell whether or not a mass looks cancerous.
Let's assume that the mass is cancerous......that will mean that your mom will be undergoing a bunch of tests initially before any treatment begins. USUALLY with rectal cancer, neoadjuvant (before surgery) treatments are undertaken to attempt to shrink the mass and to 'sterilize' the local nodal field. Your mom will likely be given a referral to an oncologist and he/she should order not only a CR scan but also some blood work. The doctor will want to check her CBC and do a CHEM panel on her to make sure that nothing else is amiss. He/she should also order a CEA (blood test) at the same time. Make sure that this test is done BEFORE any treatments begin. Many tumors (not all though) give off a particular protein which the CEA test is testing for. Many people, like me, have had big tumors and/or multiple tumors and still have a perfectly normal CEA level. Just know that if the test is normal, it does NOT indicate anything except that the tumor doesn't express that particular protein.
The 'normal' protocol for stage II and above rectal cancer is to have either chemo first, then radiation, followed by a rest period then surgery, followed by more chemo OR chemoradiation, followed by a rest period, then surgery and followed by more chemo. GENERALLY, surgery is not the first step UNLESS there are some mitigating factors...such as an almost complete blockage. Also, stage I patients usually go straight to surgery...but not always. My point is....its not uncommon for surgery NOT to be scheduled right now. Don't freak out about that!
I might also suggest that you get a referral to a BOARD CERTIFIED colon and rectal surgeon and not a general surgeon who can do the surgery. Too often, patients are referred to a general surgeon and while there is nothing wrong with that, many of us on this board firmly believe that a rectal cancer patient should be seen by a board certified colorectal surgeon. I will put the link to their site later on in this post. At the very least, get a second opinion...especially if your mother's tumor is sitting low in her rectum/anal area.
Right now, your mom will need to get the bloodwork, her biopsy results, a CT, MRI or PET scan and get an appointment with an oncologist. Start looking in your area for a surgeon and be prepared to get a 2nd opinion if that's what she wants to do. I would also suggest that your mother get a 3 ring binder, complete with dividers and start getting copies of EACH and EVERY report that is generated for her. For example, get a copy of the colonoscopy report, the biopsy report, blood work and the CT report. Sometimes, the doctors are hesitant to give them to the patient BUT...it is your right to have a copy. I have always had every place that I go copy my family doctor. That way, I can go to her (GP) and get a copy of anything.
Assuming this is cancer, you and your mom are in for the long haul. This process takes time. The tests will be have to be ordered, appointments made with the oncologist and potentially a surgeon right now (although if surgery is postponed for radiation....you can wait on finding a surgeon) and then the radiation oncologist (the one who delivers the radiation) will need to take place. All of this can and does take time. It may be a month or even 6 weeks before all of this is accomplished. Don't worry...you'd rather have all of the tests done and done correctly instead of rushing into a surgery that might be better if it waits for other treatments to first work.
Here is the link from the site that accredits these surgeons.http://www.abcrs.org/verify-a-physician-2/
Good luck. Come back and let us know what the biopsy results show.
BTW, your mom won't get a staging until all of the tests are done. Oh, I forgot....usually there is also an endorectal ultrasound that helps to determine how deeply the tumor invades the wall of the rectum and shows local nodes more clearly than a CT scan. A CLINICAL staging is done after all the tests are back. The doctors have to do a clinical staging because once the patient starts any kind of neoadjuvant treatment, pathology results would likely be different. For example, radiation should hopefully shrink or even eliminate the tumor but that doesn't mean that the patient never had cancer. Clinical staging is based on THREE components:
T - tumor depth into the rectal wall (usually ascertained by rectal ultrasound....sometimes by rectal MRI). This will be given a depth of T1, T2, T3, or T4..do NOT confuse this with the overall stage...totally different.
N - number of LOCAL nodes that appear suspicious .....likely to be affected by cancer cells.
M - number, if any, of distant metasteses...a solid tumor in another organ such as the liver or lungs OR distant lymph nodes.
Hope this all helps a little.