I used to post on here (see my old posts) threads about being worried that I had bowel cancer at 23. I was certain I had bowel cancer and told myself I have every symptom of it which included bloating, constipation, diarrhea, weight loss, mucus, stomach pains, acid reflux, water infections — you name it, I had it. I was so petrified until I saw a consultant who gave me a colonoscopy straight away and CT scan to which he found absolutely nothing except piles and some inflammation (wasn't anything major). My blood test didn't pick it anything either. 
 

My message to whoever reads this, stay calm, visit your GP and don't self diagnose! I was spending unhealthy amounts of time reading stories about young people being diagnosed with bowel cancer and on this forum which was beginning to affect my home life, work and relationship with friends and my partner. Please stay calm and I wish whoever reads this the best of luck.