It's very unlikely you have bowel cancer. That would be very unlikely at your age. 

But you should still see a doctor if this continues, not really to rule out bowel cancer but to find out what is causing it and see whether it needs treatment. There are many other options and while some of them are no big deal, others like Crohn's, ulcerative colitis, polyps might need treatment.

And even if it is something minor, which is by far the most likely option, it's very likely there is something that could stop it so that you wouldn't have any more pain.

I don't see any reason to leave it for a week, if you are worried. I'd say just make an appointment with the doctor and see what they say. A colonoscopy probably won't be necessary. It might be, but it is quite possible, even likely, the doctor will be able to pinpoint the problem without that or that they will give you a FIT test, which if it comes back clear, might well rule out some of the more serious options. Trust the doctor. They'll have a far better idea than you or any of us what investigations are necessary and how worried you should be.

And they won't think you are wasting their time. Doctors aren't just there to rule our serious issues like cancer or Crohn's. A lot of their job is about giving advice and/or prescriptions for minor complaints. There's a good chance this is something minor that a doctor will be able to give you a prescription for or advise you that cutting something out of your diet or something will solve it.

Thank you. I hadn’t considered any of the other things you have suggested, and you are right that these or something minor or more likely the causes. I’ll make sure to tell my parents about it when I get the chance. You are right, if I’m worried I should check even if it’s something minor. 

Sorry *are more likely the cause.

Also, I’d just like to add that I drink a lot of tea and coffee. This may seem random, but I’ve noticed over time that I’ve been reacting less and less well to milk. So, I may try to avoid these for a day or two and see if there are any changes. But, still I’ll make sure to tell my parents ASAP! Thank you for calming my nerves a bit.

Hi! Just wanted to update to let you know I told my mother! She’s told me to give it another day or two, but I have just found out that IBS runs in my family. Which, even though IBS is certainly not good news, it’s calmed my nerves because it least it’s a much more logical explanation than my anxious thoughts!