For the past few days I have been feeling very nauseous after eating, sometimes with heartburn and sometimes without heartburn. What scares me is that a few years ago I had experience some blood on my toilet paper, sometimes it was a decent amount. I am also lactose intolerant. After switching to a plant based diet i haven't seen any blood, it's been about 2 years. But now I been feeling nauseous after eating, also i have more gas than i usually do and I'm worried that maybe it was something serious and I waited too long. Should I be concerned about cancer with my symptoms? Please help. Thanks