I Have Suffered For Years With Chronic Diarreah With Odd

I have suffered for years with chronic diarreah with odd times constipation which when I have constipation I have found that any food consumed will hours later be vomited up undigested and makes me feel like I'm choking. I don't eat much as have a full feeling most of the time but I'm too embarrassed to go to the doctors. Unsure of what could be the cause.