I knew I was going to respect your honesty from line one. I remember being horrified when my brother sent me his colonoscopy results and telling him, "I don't want to see your ass." At the time, I didn't understand the larger picture was that he was polyp free and wanted to share.
But then my mother had ulcerative colitis and I wanted to be kept in the loop on all her poop (rhyme unintentional). If you care and fully understand what is going on with someone's body, it makes you more invested as opposed to springing it on them.
Way off the topic of guts and butts, I remember having a roommate who would make the room pitch black, not want to hear any noise and hid under the covers. It would piss me off because she'd be happy as hell one day and then a total drag the next. About a month later, she finally told me she had clinical depression. Just like that, I understood her down days. And I never rolled my eyes at them again. As frustrating as it may be, telling people (especially those who have to be around you) ahead of time will save a LOT of trouble.
I also learned to never underestimate people's health. My brother and I were constantly in the habit of stepping on each other. We'd have all the room in the world but step on each other's arm or back or something just to be a--holes. I did this to a friend of mine who I had known since I was 9. This happened in high school. She started crying hysterically, and I didn't get what I'd done wrong. I was not THAT HEAVY. Her mother told me she had sickle cell disease. The girl never told me for more than six or seven years. I just knew she stayed home a lot. Not only is it helpful to know to understand absences and mood changes, but it could also help your loved ones from doing something stupid.
Anyway, good read.