Do you know of any peer-reviewed scientific double blind studies showing this?
I was not speaking for myself. I was reiterating what I was told bby a prominent gastro specialist who believes that fiber is habit forming for all the reasons I laid out. Check back with me in five years and tell me whether you still feel the same way.
This is incorrect advice. In most cases of constipation, fiber is helpful. It works by adding bulk to the stool which makes the stool easier to pass. In some rare cases fiber is not helpful. When someone has a motility disorder where the colon is "sluggish", adding more fiber to the diet just creates more stool that needs to be moved through the colon, which someone with a motility disorder has trouble doing. Just because fiber didn't help you and made you worse, does not mean that is won't be helpful to most people.
The presence of mucus is normal in the colon. It is the loss of it that signals a problem. It is common in IBS and more so in those patients who are trying to manage it with excess fiber. The colons of older people cannot take a lot of fiber and currently almost all medical sources are recommending increasing fiber.
Before this becomes a bigger problem, prolapsing hemmorhoids for instance, you may want to seek out a very good gastro specialist. If he sings the more-fiber-more-fluids song, keep looking. And get your mnother on a FODMAP elimination diet ASAP.
I am not a doctor, but just someone who spent about 15 years getting progressively worse on the more-fiber chant and finally found a gastro team that has begun to ask questions about why no one seems to get better on that advice.
Mucus may be from intestinal parasites - this can be checked by stool test for parasites. Mucus is also produced by adenomas or colorectal carcinoma (how old is she?). This would require colonoscopy.
Mucus may be from irritable bowel syndrome. "Low-FODMAP diet" may help in this case.
http://www.medhelp.org/user_journals/show/118248?personal_page_id=801