Hello, and I hope I can help you today.
A full term healthy infant is quite strong, and many mothers start to feel pain when the baby kicks and punches you inside your uterus. Furthermore, the kick or other blow to one area can start a contraction in the area that was hit. Pain in your
rectum or vagina can come from the baby literally hitting or pushing on it with a fist or elbow (if the baby is head down).
It is also possible, because of the
diarrhea you describe, could just be cramping in your intestines from a
stomach flu of some kind.
Either way, as long as the baby is moving well and you have no vaginal bleeding or leakage of fluid, and also have no fever or
vomiting, there is no danger to staying home and taking some kind of painkiller (like
Tylenol or
Paracetamol, which are safe in all times during
pregnancy) and try to lie down and rest and hydrate yourself well.
If at any point your uterus starts to contract regularly or the pain does not go away when you rest, I suggest you see your OB provider or go to the hospital for evaluation.
I hope I was able to adequately answer your question today and that my advice was helpful.
Best wishes for the rest of the pregnancy,
Dr. Brown