I've had a series of on-going problems for about 8 months now after a trip to South America. During the time I was there (approx. 2 months) I was having constant diarrhea for about 7 weeks, and went to the hospital there thinking I contracted a parasite or virus. They gave me a shot in the bum, and took blood and urine samples which came back negative. Since then, I have had chronic stomach/abdominal pain and discomfort with on and off diaherrea and constipation acompanied with flatulance. My stools since this time have become mucus-y with occasional bouts of blood in the stools or when I pass gas. Ive been experiencing constant fatigue, headaches, and body aches. And i've also gained about 30 lbs since the beginning of the year. I'm not sure if it is all related or not, but I am beginning to be concerned. I've made dietary changes for a few weeks to see if it is IBS, but nothing in particular seems to effect it (dairy makes it worse, but I normally stay away from diary products anyway.) Should I be concerned about parasites or something else?