When you sit on the toilet and do a #2, do you take a quick peek before flushing? I suspect that many people do check their poo to make sure everything looks OK—and in my opinion, there’s nothing wrong with that.

But some people go overboard, examining each bowel movement as if they were reading tea leaves. They fret, Is it shaped properly? Is the texture all right? What does that color signify? And why does it look so different today compared with yesterday? I’ve even heard of folks who take photos of their supposedly substandard stools to show to their doctors!

To allay such concerns, I contacted Alvin Newman, MD, a gastroenterologist at the University of Toronto and author of The Essential IBS Book. He told me that stool is composed mainly of water, nonabsorbable “food stuffs,” bacteria and sloughed-off cells from the intestinal lining. Stool color is derived from bile pigments and food residues, so it can vary significantly—with dark brown, light brown, yellow, greenish and multicolored all qualifying as normal. “Many things can affect stool color. Bismuth (such as in Pepto-Bismol) and iron can turn stools extremely dark. Beets can turn them reddish. Green stool usually means only that intestinal contents have moved through the digestive system quickly,” Dr. Newman said.

Solid-waste elimination is a variable process, so there also is a wide range of normal when it comes to stool size, shape and consistency. Even mucousy stools (which a coworker asked me about) are generally not worrisome, Dr. Newman told me. “In the absence of other things like blood or severe pain and a change in bowel habits, mucus in stool is merely the bowel’s way of lubricating itself,” he said.

Bowel movement frequency can vary greatly, too, from three per day to three per week, yet still be within the normal range—so skipping a day or two does not necessarily signal a problem with constipation. “It is probably fair to say that the fear of constipation is much more intense than the fear of diarrhea, even though very few people have ever died of constipation, whereas diarrhea may be life-threatening,” Dr. Newman noted.

Clearly, there is no such thing as “perfect” poo—and no reason to worry over every little change. But that’s not to say you should ignore it altogether. Do see your doctor without delay if…

  • Your stools are bright red, dark red, burgundy, maroon or black. Such colors suggest the presence of blood. The source could be something as simple as a small hemorrhoid, but you should be checked for other conditions, such as an anal fissure (a tear in the tissue lining the anus), colon polyp or colorectal cancer.
  • You pass four or more watery or liquid stools per day for several days. Severe diarrhea can easily lead to dehydration.
  • You have severe constipation—for instance, only one bowel movement per week plus frequent bloating and abdominal pain. You may need to be screened for slow-transit constipation, a condition in which things move very lethargically through the bowel. One clue to this condition is if adding fiber to your diet, which normally would ease constipation, instead makes your symptoms even worse.
  • Passing stool is consistently painful. Your doctor will want to investigate possible causes, such as severe hemorrhoids, an anal fissure or anal abscess (a painful boil-like swelling near the anus).

Some years back, the Scandinavian Journal of Gastroenterology published the Bristol Stool Chart, which showed and described seven different types of stools (you can check it out at www.IbsGroup.org/bristolstool). You may find the chart to be a useful communication aid when discussing bowel movement concerns with your doctor. But remember, unless your doctor specifically asks for a photo, there’s no need to take your camera into the bathroom.