I'm just going to dive straight in, 

since a young age I was going to the toilet up to 4 times a day mostly diarrhoea then all of a sudden about 9 months ago I started suffering from constipation, I noticed I have had undigested food in stool at times and my stool colour changes colour a lot never red though. 

i have been to the doctors multiple times in the last year they have done bloods which have always been normal and just put it down to my IBS and anxiety, I started suffering from reflux last year but no longer get it and it pains in the right side of my lower stomach and back almost achy at times.

I am really scared that there is something more sinister going on but I'm not being listened to because of my age.