Re: rectum blood
It is very difficult to diagnose a ruptured cyst. The only way is to see fluid in the cul de sac region and "guess" that this occurred due to a ruptured cyst (fluid in the abdomen is caused by a multitude of other things).
You seem to be quite certain that the blood is originating from your rectum so see if your family physician can refer you to a gastroenterologist, a specialist who deals with these things. A simple sigmoidoscopy may uncover the reason very quickly.
This is a procedure that is done in about 15 minutes while you are awake where they look at the lower third of the colon (if you like, you can also watch on the monitor). If the blood you saw was bright red (as opposed to brownish or black) then more than likely it is coming from this area. The doctor will be able to see if you have internal or external hemmorrhoids or fissures that are causing the bleeding. When I had this procedure done, my surgeon only required a couple of enemas on the morning of the procedure. This was quick and easy and cleaned out the area very well so that the surgeon was able to see what was there.
If a colonoscopy is required (ie. to look at the entire colon) then you will be sedated but everyone I know who had this done (including my mom) says that they feel extremely well rested when they wake up. The prep for this one is a little longer and you have to drink something the night before in order to clean out your entire colon.
If you are having abdominal pain with rectal bleeding I would strongly suggest that you get a referral to a specialist who deals with these things so that you can find the reason and fix it. Abdominal pain with bleeding may be suggestive of diverticulitis or inflammatory bowel disease (ie. Crohn's) or irritable bowel syndrome to name some of the most common reasons.
Don't go by what they told you in the emergency room. Get it checked out properly just to be sure.