So, kinda yes. In first few months after surgery, headaches following orgasm were not unusual.
Now, headaches associated with diarrhea not so clear cut. It was/is more complex than just "diarrhea and then headache" because the situation would also be accompanied by an urgent need to vomit aggressively. This actually occurred a year or two before surgery and then has occurred multiple times in the nine years since surgery. The docs had no idea what this was. After much research on my part, I decided it was likely caused by tumor's interaction with the vagus nerve, which is the 10th cranial nerve and wanders throughout the body. I proposed this explanation to my surgeon and he agreed it seemed likely, he just had not seen this before.
If you google "vagus nerve problems" you may find a number of issues that sound familiar.
I hope this is helpful.