I am no expert but my understanding is that it could be lots of things. The first thing my mind would jump to would be hemorrhoids, but yeah, polyps and cancer are probably options too. I don't know enough to say whether it could be IBD without inflammation markers. And of course, there are probably plenty of things neither you nor I have heard of that it could be too.

The consultant will be able to give you a better idea of what the options are.

Also, when it comes to cancer and to a lesser degree, polyps, your age really is a major factor. I mean, I doubt it's the most likely option or even one of the more likely options no matter how old you are, but the younger you are, the less likely it is. I had some issues with rectal bleeding, weight loss, some loose stools and trapped wind when I was 40 and the consultant said that at that age, I'd be "the most unlucky person in the world" if it turned out to be cancer and that that would be the least likely of all the possible options. I know your symptoms are different, but just to stress that there are many options.

Thank you for the reply, I really appreciate the helpful message. I'm 25 so I guess at my age it will be unlikely that it's cancer, but I suppose with the symptoms I'm getting you just never know I guess. I was wondering if it could be IBD, but like you say without any inflammation detected how likely is that. My guess is it's probably hemeroids, but it's difficult to say and I'm not sure if that would produce mucus. I will update this thead and reply to you when I have spoken to the consultant, I will let you know what they say.