I recently had a colonoscopy. My doctor said everything was fine, but when I read a copy of my report, it said that I had "melanosis coli." What does that mean? Should I be concerned?

Answer: It's nothing to worry about. Melanosis coli just means that the colon lining is stained dark because you've been taking a type of laxative like Senakot that can, over years, stain the walls. It doesn't happen overnight or with occasional use or when folks with constipation use fiber laxatives like Citrucel, Metamucil or Benefiber.

Other than having a stained inner colon lining, everything is visibly fine with your colon (as your recent colonoscopy confirmed). There's no increased risk of cancer from melanosis coli. You have a chronic constipation problem that may be due to an age-related slowing down of peristalsis (waves of digestion) or perhaps constipation-predominant irritable bowel syndrome.

Be sure that you're drinking lots of water and fluids daily (eight glasses a day is a rough suggestion). Natural fiber from drinking a tall glass of warm prune juice daily can be very helpful. I'd discuss your constipation problem with your gastroenterologist, since he may suggest a better remedy.

While we're on the subject of color, those who take supplemental B vitamins may notice that their urine is bright yellow.

It's just the color of the B vitamins and nothing more.

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No scientific proof that asparagus is diuretic


I notice that after eating asparagus, I seem to have to urinate often. A friend of mine who is into herbal medicine says it's because asparagus is a diuretic. Is that so, and if so, why?

A: There's a lot of anecdotal information out there that refers to the diuretic ("water pill") properties of asparagus, but I have not been able to find any human studies that verify this. Potassium has a mild diuretic effect, and since asparagus is relatively high in potassium, one might theorize that there could be more urination after eating asparagus. Anecdotally, I too have noticed a diuretic effect just after eating asparagus.

Other foods that are said to have a diuretic action include: celery, onion, eggplant, melon, dandelion, watercress, and parsley. While occasional use of these foods for mild fluid retention is OK, I would strongly recommend that they not be used for blood pressure control, heart failure, or to help you lose weight. Avoiding excess salt and sodium is just as effective and a lot safer.