When I go for a poo it's got loads of mucus no blood and a really bad foul smell my tummy always rumbles/vibrates loads even after eating?

Mucus for how long. If you have had mucus more than 3 weeks and you are not getting over an infection then go see your doctor. Otherwise, this can happen with a "stomach" infection and it may take a few days to return to normal. Avoid dairy if that is the case.
Need testing. mucous in your stool is concerning for some infection or other inflammatory process in your bowel. at the minimum u need stool testing, and may need colonoscopy.
Digestive problem . it sounds like you have a digestive problem. I would recommend being evaluated by your primary physician who can do tests on your stool to look for infections. If he/she can't figure it out then I would recommend a referral to a gastroenterologist. .