Does Long Thin Poop Mean Colorectal Cancer?

You can learn a lot about your health by your stools. If you have long thin poop coming out, it deserves a closer look.

First off, know that doctors often refer to this symptom as “Stringy stool”. It can be caused by something as simple as not getting enough fiber.

It can also be something more serious, like colon cancer or rectal bleeding (less likely but still possible).

Even chronic conditions like IBS have been known to cause it. In this article, we’ll talk about all the potential causes of this strange symptom.

What is Stringy Poop?

Stringy poop refers to stools that look very narrow. These stools are sometimes so thin that they resemble a ribbon.

Normal poop is supposed to be about 2-inches in diameter. But with stringy feces, it comes up narrow and flat, which is definitely isn’t normal from a physiological standpoint.

In some cases, it may be associated with other symptoms, like:

If you have several of these symptoms, then you should talk with a doctor as soon as possible to rule out something serious.

Bottom Line: Normal poop is supposed to have a diameter of about 2-inches. Anything less than this should be investigated.

Common Causes

Here are some common causes for this symptom:

  • Constipation: Low fiber and dehydration are the two most common causes for constipation. When you eat fiber, it makes your stool bulkier. The same with fluids. If you aren’t getting enough of either one, it can cause you to release long thin poop. If you’re young, healthy, and aren’t experiencing any other symptoms, constipation is a likely cause.
  • Colorectal Cancer: A lot of people freak out because they automatically assume that they have colorectal cancer. They believe that tumors in the digestive tract forces the colon to narrow, resulting in stools that are thinner than normal. However, it’s important to know that if you don’t have any other symptoms, the chances of it being colorectal cancer are low.
  • Abdominal Hernias: You might have a trapped abdominal hernia that’s preventing the normal flow of poop in your digestive tract. Some hernias can cause the area between the rectum and the anus to narrow, which as you can guess, will cause the stool to narrow as well. Be sure to ask your doctor about whether you might have an abdominal hernia.

Generally, you don’t need a colonoscopy if a stringy stool is the only symptom you’re experiencing (unless, of course, you want to for peace of mind).

Additionally, some intestinal parasites, including giardia, can cause long thin poop. People with parasitic infections usually have associated symptoms like weight loss, fatigue, nausea, and cramping.

If you don’t have these extra symptoms, it’s unlikely to be a parasite causing your symptom.

Bottom Line: Common causes for thin stools include constipation and abdominal hernias. Less common causes include cancer.

Inflammation in the Colon


Conditions like Crohn’s disease and ulcerative colitis cause inflammation in the colon, which in turn, may cause your stools to become pencil thin or flat.

While Crohn’s disease can’t be cured, there are treatments that can help with the pain.

Some people with Crohn’s disease remain symptom free for most of their life, while others live with chronic symptoms that never go away.

Bottom Line: Inflammation of the colon, which is common in people with Crohn’s disease, can be a cause of your symptom.

Stress and Anxiety

As you might know, there’s a strong link between the brain and the gut. Scientists have shown that stress can cause your digestive system to go “out of whack”.

Fortunately, there are ways to reduce stress, including:

  • Meditation
  • Exercise
  • Stretching
  • Writing in a Journal
  • Listening to Music

Basically, try to do things that are going to release your body’s natural “happy hormones”. Exercise releases endorphins, which is why it’s the most recommended option.

Bottom Line: Stress and anxiety can have physical affects on the body. In fact, there’s a strong link between the brain and gut.

IBS and Long Thin Poop

It’s not uncommon for people with IBS to also have long thin poop. IBS causes your bowel habits to do things that aren’t considered physiologically normal.

For example, IBS can cause mucous to build up in your stools, which ends up giving them a stringy appearance.

If you have IBS, focus on eating better. Specifically, eat fewer animal-based foods and more plant-based foods.

While this won’t necessarily make your symptoms disappear, they should reduce them dramatically.

Bottom Line: Patients with IBS can get narrow stools due to thier bowel habits. Eating a diet that’s rich in fruits and vegetables should alleviate many of your symptoms.

Sometimes There is No Obvious Reason

Sometimes your doctor won’t find any root cause for your stringy stools. If you’re only having this symptom occasionally (on and off), then there’s no reason to panic.

However, be on the lookout for additional symptoms like fever, rectal bleeding, and abdominal pain.

If you have these, you should call your doctor. They’ll go over your symptoms and prescribe the necessary treatment for helping you get better.

Bottom Line: Unfortunately, doctors won’t always be able to pinpoint the cause. Be on the lookup for additional symptoms like rectal bleeding or pain.

Tests That Can Determine the Cause of Stringy Poop

fecal occult test

What tests will your doctors do to determine what’s going on?  The most common one is the fecal occult test. With this test, the doctor will check for blood in your stool.

The stool sample test is designed to check for the presence of bacteria and parasites, while standard blood tests are used to rule out celiac disease.

If your doctor thinks it’s something serious, they may give you a sigmoidoscopy to scope out your lower colon.

And finally, a colonoscopy can be performed to examine your entire colon.

Bottom Line: There are various diagnostic tests that can be performed to determine what you have. The fecal occult test is a common one.

How to Get Rid of Constipation

As we mentioned earlier, if you have no other symptoms, then it’s probably constipation causing your long thin poop. Starting today, drink more water and eat more fiber.

Try to drink a minimum of 8 glasses of water per day (more if you’re active). Also, start eating some of the following foods since they contain a lot of fiber:

  • Avocadoes
  • Berries
  • Coconut
  • Figs
  • Black Beans
  • Flax Seeds
  • Pop Corn
  • Dried Figs

You can also try fiber supplements like BeneFiber. As you get more fiber in your diet, your constipation should start to go away. If it doesn’t, see your doctor to talk about other potential treatment options.

high fiber foods

If You Have Celiac Disease

If you have celiac disease, and it’s causing you to experience stringy poop, then eliminate all gluten from your diet.

Foods that have a lot of gluten include oatmeal, brown rice, and wheat bread. Minimize or eliminate these altogether.

This should help keep your symptoms under control. Here’s a video that talks about what celiac disease is and how gluten makes it worse:

If You Have an Infection

If stringy poop is being caused by an infection from a parasite, then you’re going to need anti-parasitic drugs.

Many parasites will be eliminated using a single treatment, but others will be harder to kill, requiring more treatments.

Don’t try to use herbal remedies unless you’ve gotten them pre-approved by your doctor first. You don’t want to risk making your symptoms worse.

Bottom Line: If your narrow stools are being caused by an infection, then anti-parasitic, anti-viral, or antibiotics will be required.

If You Have Colon Cancer

If you have colon cancer, then treatment options will be chosen based on whatever stage the cancer is in.

If the tumor is small and the cancerous cells haven’t spread to distant organs, then the prognosis is good.

As you can imagine, it becomes more complicated if the cancer is advanced and has already spread.

Bottom Line: Not all cases of narrowed poop is a result of colon cancer. An MRI or CT scan can help rule out cancer.


Most of the time, long thin poop happens because you aren’t getting enough fiber and/or water in your diet. Even if you’re not feeling thirsty, force yourself to drink.

Try to make a game out of it and see if you can reach your goal of 8 glasses by a certain time. Sporadic cases of stringy stools are usually nothing to worry about.

You should only be concerned if it becomes chronic and if you start to experience additional symptoms.

Ask a Question: If you want to ask a medical doctor a question that hasn't been answered in one of our articles go to: Ask a Medical Doctor About your Symptoms

Did you find the information in this article helpful?


  • Are you sure normal stool has 2” diameter do you realize that 99% of the time with 99% of people it’s 1” dia. Such info should be carefully posted so it doesn’t have people un-necessarily worried

  • Under Celiac Disease, this otherwise informative posting makes an error in saying that brown rice contains gluten. It does not. It also implies that oatmeal contains gluten. Again gluten is not a component of oats but there is a risk of it being contaminated with gluten if the oats have been grown in a field previously used to grow gluten containing cereals (wheat,rye, barley, spelt) or processed later in a factory that also processes gluten containing cereals or their derivatives.

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