The Concerning Poop Myth Health Experts Want You To Stop Believing

People don't generally like to talk about pooping (it's a gross bodily function, after all), and that could be why there are so many myths about it. For instance, the brown note poop myth has been debunked by science, with researchers finding that this supposed high-intensity infrasound doesn't trigger uncontrolled diarrhea. Another myth that science has debunked is that narrow or pencil-thin poop is a clear sign of colorectal cancer.

On the contrary, seeing a thinner stool than usual in the toilet after a bowel movement doesn't definitively indicate that you have colorectal cancer. That misconception likely emerged in the 19th century based on the caliber of a stool decreasing with the presence of a tumor in the colon. Instead, a study published in Digestive Diseases and Sciences found that pencil-thin poop alone is not enough to even warrant ordering a colonoscopy.

Part of the reason is because researchers have found that, when narrow stool is the only symptom, fewer than 2% of the cases result in malignancy. Another reason is that it's normal for poop to change shape depending on diet, hydration level, and benign or functional underlying conditions. As a result, scientists believe that unwarranted colonoscopy referrals are an unnecessary risk and waste of healthcare resources.

In more than 95% of cases when colonoscopies are ordered, and the only symptom is narrow stool, the cause turns out to be benign. Sometimes, stringy stools are a sign of a parasitic gut infection, pelvic floor dysfunction, or temporary inflammation. About 90% of the time, though, the cause is functional constipation or irritable bowel syndrome (IBS).

Functional constipation means having fewer than three bowel movements a week, and it can happen if you don't drink enough fluids, eat enough fiber, experience a lot of stress, or have a sedentary lifestyle. As a result, the stool stays in the colon for longer than usual, losing water and becoming harder. If the anus or rectum are also somewhat contracted, the feces can emerge thinner than expected. It's important to see a doctor if the issue persists because gross things can happen if you don't poop for a week, such as impaction and hemorrhoids that can also cause pencil-thin stools.

However, one of the most common causes of stringy stool is IBS, a gut-brain disorder that 10% to 15% of the population deals with. Since it can present with diarrhea or constipation, it's common for people who have it to experience consistency and frequency changes in their stool, as well as abdominal cramping or pain, bloating, gas, and other symptoms. These symptoms can be triggered by a range of things, including diet and stress. Despite that, IBS is a non-life-threatening, manageable condition.

While occasionally having pencil-thin poop with no other symptoms isn't really a cause for concern, experiencing long-term stool changes alongside certain other symptoms is something that you should discuss with your doctor. It's similar to when your poop floats instead of sinks, which can be caused by everything from higher gas or fat content, to pancreatic cancer when more significant symptoms are present.

When narrow poop consistently occurs for more than a few days and is accompanied by anemia (low iron), bowel incontinence (leaking stool), blood on or in the stool, vomiting, or weight loss for no explainable reason, your doctor may do some testing for colorectal cancer. A physician may test for cancer of the anus if your poop changes are accompanied by a growth or swollen lymph nodes around the anus, discharge from the rectum, or bleeding, itching, pain, or pressure in the rectum.

Even if there are no symptoms present, the U.S. Preventive Services Task Force recommends that adults start getting a colonoscopy for colorectal cancer screening at age 45. That's because almost 94% of new diagnoses every year are in people aged 45 and older, with patients between 45 and 54 accounting for nearly 16% of that (per the National Cancer Institute).