Hello , I have a lymph node in my groin that causes a lot of pain , I have been tested many different times for STD S they all came back negative , I was just wondering what type of infection is my body fighting off for the lymph node to be there ....I have been having trouble with bowel movments since last summer , I went to the emergency room and got a ultra sound on my intestines last summer 2014 they said I was very backed up and that s what was causing all my abdominal pain during the time ...over the summer I really was not having regular bowel movements tried to add more water and veggies to my diet it helped somewhat ....so now 2015 I develop a lymph node and diarrhea and constipation & the pain of the lymph node hurts more if im trying to relax ,stressed or on my feet at work all day ...im confused please help