My CRS said that some people hold their stress in their bottoms and I am one of them too. Even as a kid I remember when I was upset I could feel my butt clenching.
The digestive system is one of the most sophisticated systems in the body. There are a lot of serotonin receptors in the gut too.
I grew up with Southern parents and there was a real climate of properness and that certain things are not discussed. My mom still doesn't really want to know what is going on with me. You can tell she is just so embarrased and uncomfortable. I was very proper and modest too until this happened. I remember I asked my husband to leave the room when they were performing a cervical check to see if I was in labor. He wouldn't budge though and after labor started I wouldn't have cared who saw my bottom. But dealing with pooping and anal problems was a different story. I was brought up to believe (tongue in cheek) that men don't know that women go to the bathroom and you keep that very private. But now after dealing with this we spend way too much time talking about it. He asks me so many questions about how it went in the bathroom.
Here is an example of love: After I had my hemorrohid surgery I had problems having a BM. He told me to just go in the tub and he would clean it up. I didn't take him up on it because I didn't want to sit in my sh*t but it was a very thoughtful and selfless gesture.