sorry to hear of your anxieties.  Firstly, you are young to have bowel cancer as most cases are over 60.  Secondly, a lot of your symptoms could be related to other problems of the bowel such as IBS or IBD or even coeliac disease  However, you really need further testing so see yoru GP who hopefully, will get further testing.  One of the tests they do, is look for tiny amounts of blood in the poo.  

As toothfairy675 said, your symptoms could be due to a whole lot of things. Something like IBD is probably more likely than cancer. 

Over the summer, I had rectal bleeding, some weight loss (about a stone in a year), a couple of weeks of really bad trapped wind and occasional loose stools (about once a week). The doctor said that at my age (40), the odds of cancer were less than 1% and that the most likely thing was hemorrhoids with IBD a possibility. I had a colonoscopy and sure enough, what they found was hemorrhoids. 

It is very likely you will get an answer straight away. It depends on what they find. They will be able to tell you straight away if there are any polyps or if they took any biopsies. If they did, you will have to wait longer as they will have to test them and give you the results afterwards. If they don't take any biopsies and you have no polyps, they will be able to tell you that right away.

I am no expert but as far as I know, bowel cancer can be hereditary, but it is also quite common at older ages so having a grandmother who died of it does not necessarily mean you are at risk. I told a doctor that my grandfather may have had it and he said that was too distant to be a concern and wanted to know if either of my parents or any siblings had had it, which they didn't.

Thankyou both for your replies, I have a feeling it's ibd not sure what type but still have this anxiety esp because of my appetite loss and such a significant amount of weight loss over 3 stone, if the results of colonoscopy come back fine what happens after that? Would they send me for further tests ? 
thabks againx

Yes, you are right.  Bowel cancer is hereditary, but they are only interested in close relatives who were diagnosed before the age of 50, I think, so anyone older it is likely due to wear and tear than genes.

I am sure that your GP has investigated anxiety, but this can cause (or make things worse) in the bowel.  The hormones released when you are constantly anxious make the bowel move so much quicker and hence diarrohea.  I have IBS which means that whenever I get worried, my first symptom is running to the toilet.  Secondly, you mention itchy skin.  Again, anxiety plays a huge part in itchy skin as the same hormones arrgravate the nerve endings.  I suffer terribly from itching because of anxiety.  During my colonoscopy, my feet were itching so badly, it worked a treat as a distraction!  As Margaret says, you should get the results immediately.  They may need to send off biopsies to the lab but they will be able to see the cause.

I have all of these symptoms and more and finally after months I'm staring to investigate them properly good luck with your colonoscopy on the 6th please let us know how it goes x