Could be something else like IBS, Crohns, food allergies , parasites, bad bacteria overgrowth.
Best to get on a good natural diet and take expensive acidophilus supplements for a couple months and then see how you are. Also use the pulse test to know and avoid the foods you are allergic to: http://www.dragonfly75.com/eng/pulsetest.html

LISTEN TO ME !
ive been with same situation as you i 10 years straight and the doctors said im making things up and blala bla gave me setoried creams which made things worse and they told me diet has nothing to do with it and stuff and ive listened to them and ive got to a level bad of candida at one point in my life like i think between the people who has it i was like the 2% who has the worse of it.
Dont listen to anyone ! not even doctors ! you will get worse and worse trust me
go on the Gaps Diet as i do, Even if you have candida or not This diet will 100% you no matter what kinda of illness you have,
stop gluten, peanuts, corn, Milk , processed foods and more just go to the gaps diet.
i was just like you so naive that the doctors knows best and ive almost killed myself like 10 times because of this and now im trying my hardest to heal so you should to !
and if you think diet and health problems are'nt link then you are an idiot !you are what you EAT,
Never forget the message that ive sent you right now and good luck on your journey to heal.