How do you handle IBS?

my ex boyfriend had this NOT AS BAD...but it was caused from stress and when we would fight he would get reallllly sick....he also has slight OCD... GO BACK TO YOUR DOCTOR b/c if your not eating thats NOT good at all & yeah u might be staying thin and skinny but one day its going to just be so bad & you WILL gain the weight back.....GO SEE YOUR DOCTOR PLEASE!!!!