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 ?

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.

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

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.