Stomach pain in people with dementia. Any thoughts?

My first thought would be constipation. My Aunt with mod/adv dementia was yelling in pain which was way high up, under her breast. Her family caregiver was giving her Tylenol PM and it was making her constipated. We transitioned off of it, and added in more moisture-based foods she likes (Jello, soup, cukes, watermelon, etc) and she gets as stool softener. My 91-yr old mother (a former RN) was also having the same pain and refused to believe it could be constipation but she has IBS. Constipation would be the "easiest" to diagnose and treat.

My Mother's vague stomachs pain has been found to be all of these; appendicitis, bladder infection, kidney infection, low oxygen. Plus I suspect dehydration & constipation. I also wonder about small vessel problems, as history of TIAs. Have read small blood vessels can rupture or clot in abdo area too, not just brain.

It might be helpful to track what she is eating to see if you can find a pattern, I remember that one of our regulars mentioned that one of her parents developed a new lactose intolerance.

What you are going thru is so frustrating! I have a couple of suggestions that might help because we kind of have some of the same issues with my aunt (frequent ER visits etc.)
I found that with my aunt she is mostly fine when she is distracted by something she wants to do, however, when she is bored, anxious, or looking for attention, her stomach hurts.
To rule out any physical issues she has been to specialists who found nothing wrong and her regular doctor prescribed daily IBS meds, benefiber, and a pain killer if needed. She needs a daily reminder to take these. She self-medicates with laxatives - you might want to check and see if your mom has laxatives or is using something that might be causing the stomach pain?
Someone mentioned diet already but it might be worth considering if she is eating frequently enough during the day, I'm not sure if hunger is something that registers quite the same way in someone with dementia.
If it isn't physical maybe checkout Diana Waugh, she has a video on YouTube, "How to talk to someone with Dementia" She talks about how when you ask how they are doing the response that the patient gives can sometimes be inaccurate because the question is confusing or demands too much of them. She specifically mentions the stomach complaint.

I recall a man with dementia who for a few years had been complaining of throat pain, Every time he complained, the medical exams and tests came back normal. Then, I lost track of him for some time. One day unexpectedly, I bumped into his wife at the supermarket and I asked her about her husband. She replied: "My husband died recently of throat cancer". Just a thought.

Is there a constipation or diarrhea component here? Could she have IBS? Does she take something like citrucel daily to regulate her bowels (good for preventing BOTH diarrhea and constipation, adds fiber, don't substitute metamucil which will give added gas and bloating and pain in my opinion; it ferments differently in the gut).
As she has had all the test it is difficult to say what this could be. It isn't really an age related issue often enough. Just found out about a diagnosis of the more rare blood dyscrasia called hemochromotosis in someone when everything else was negative (its an issue of iron in these cases, too much of it, and causes abdominal pain).
Often when we can't come up with an answer we move to "It's a head thing" but the truth is, where there is pain there is usually a reason, and medicine just has a hard time finding it.
I would say if you have been to a gastroenterologist, had stool testing, blood testing and any scans, then you have addressed it well as you can. Hoping this is not anything serious. A recent OP had an elder that had obstruction and perforation of intestine so this should not be ignored; but you have followed it up it seems as best you can.
It is hard to get a really GOOD description from our elders sometimes, such as when pain hits, if related to food, upper or lower, relieved by passing flatus or not. But try to get as good a history as you can when you speak to your Mom. Everything is a clue. Look on it as a mystery and collect all the data you can.

If there is nothing organically wrong with mom's stomach, perhaps it's related to a food she is eating. Does she have GERD, by chance; acid reflux? If so, there are many foods that aggravate GERD horribly; like tomatoes & chocolate. I'd keep TUMS handy for her as well as Alka Seltzer b/c bicarbonate of soda tends to help with upset stomachs, if she is able to understand that when her stomach hurts she needs to take something to help fix it.

If she's still living alone and calling 911 frequently, this is probably the time to get her in-home help or placed in Memory Care. Someone who was dx'ed with AD 4 years ago really should not be living alone b/c too many things can happen; catastrophic events lie in every room of the house and she can hurt herself quite easily or burn the place down by forgetting the burner on the stove is on. "What to do" is to get her some help so they can give her some Tums or even Pepto Bismol when she complains of a stomach ache and prevent her from calling 911.

My elderly aunt with AD was calling 911 so much (in Assisted Living) that eventually, her daughter had to remove her telephone, which she did not want to do.

Wishing you the best of luck.