Sometimes when you have a BM you can stimulate a nerve called the vegal nerve, that's why some people actually pass out on the toilet especially if they already have heart problems, It can cause deacclerations in the heart if you stimulate it. I would check with your doctor this could be dangerous

Sometimes even when you just have a little infection like a cold or even your say "I don't feel good my throat hurts" your lymph nodes swell because they catch some of the infection. I would check with your doctor just to make sure!