My mother's symptoms seem to be trolling me. Every time I think I have something to grab onto the symptom mysteriously disappears only to be replaced with something else. Pain in the lower back, itchy lower back, impacted colon, blood in the urine, black stool, hacking cough. All there and then gone just as quickly. I can't keep up.
Its obvious your mom is very ill. And you’ve had a very long row to hoe. Don’t stress out over every symptom and feel you need to hang onto them or figure out the why’s and wherefore. Find a peaceful place, if even in your mind and go there. For me, it’s redecorating my bedroom in my thoughts. It works.
Cancer would still be a kinder end than watching someone slowly become everything they would have hated.
It's hard not to "awfulize" in this situation, but be aware that the fact that a doc says "we need to rule out XYZ" does not mean that you need to "worry".
The way I started to look at it when my mom got to this stage was "there is NOTHING we can do to fix this; we can only ameliorate and treat her symptoms and above all, keep her pain free". That line of thinking helped me a lot. It took a long time to get there.
Constipation doesn’t cause colon cancer and I don’t believe it’s a sign of it either. If Mom was diagnosed with cancer, would Dad allow her to be treated? Or would he ignore it and hope it goes away because he selfishly doesn’t want to be poor and alone? All these things that are plaguing your Mom are part of her issues. She sounds very angry and unhappy. The doctors need to handle this. There really isn’t much you can do except agonize over what to do. And as long as your father has his head in the sand and you don’t force the issue with him nothing will change.
Constipation can be a sign of colon cancer if the growth is large enough to obstruct the colon. If it goes on long enough it can put pressure on the other organs and eventually cause a heart attack.