You can learn a lot about your health from the appearance of your stool. Stringy stool may be caused by something simple, such as a low-fiber diet. In some cases, the cause is more serious.

Stringy poop may also be referred to as stools that are pencil-thin, ribbon-like, thin, or narrow. Normal stool is about one to two inches in diameter. Stringy poop is narrow and, in some cases, almost flat, giving it a stringy appearance. It may be solid or loose.

Stringy poop may or may not be accompanied by other gastrointestinal symptoms, such as:

There are several reasons your stool may be thin.

Constipation

Constipation may be caused by a low-fiber diet and lack of fluids. Fiber adds bulk to stool, increasing its size. If you don’t eat enough fiber or drink enough fluids, stool loses its bulk and may become thin and stringy.

Increasing your fiber intake may be as simple as making a few changes to your diet.

  • Whole grains, like bran, whole wheat, or oats, are an easy way to increase your fiber. When buying groceries, look for a whole grain bread, pasta, or cereal.
  • Getting your recommended daily servings of fruits and vegetables can also help you to increase your fiber intake. Look for fruits and vegetables with five or more grams of fiber.
  • Beans are another great source of fiber. Throw beans in a salad or add them to whole grain rice for a fiber-rich meal.

Colorectal cancer

Many people panic when they see stringy stool because they’ve read or been told it’s a sign of colorectal cancer. The theory is that as one or more tumors grow, the space inside the colon narrows, resulting in thinner stools. A 2009 review of medical literature came to a different conclusion.

The review found that stringy or “low-caliber” stools occur whenever people have loose stools. It concluded that if low-caliber stool occurs without other symptoms, the cancer risk is low. Other symptoms may include:

  • rectal bleeding
  • changes in bowel habits
  • the persistent urge to have a bowel movement
  • left-sided abdominal pain
  • anemia

The review also suggests that referring people for a colonoscopy only because they have low-caliber stools unnecessarily puts them at risk and strains the healthcare system. Despite these results, thin stools are still considered a red flag for colorectal cancer by many in the medical community.

Additional causes

These other conditions may cause narrowing in the colon and lead to stringy stools:

  • fecal impaction
  • colon polyps
  • trapped abdominal hernias
  • anorectal strictures, or a narrowing between the rectum and anus
  • distended, or stretched, colon
  • twisted bowel, or volvulus

Some intestinal parasites, such as giardia, may cause loose, thin stools. If you have a parasite, you may have other symptoms such as:

  • cramping
  • nausea
  • weight loss
  • fatigue

Conditions that cause inflammation in the colon, such as Crohn’s disease or ulcerative colitis, may cause loose, thin stools and diarrhea.

Irritable bowel syndrome may cause changes in bowel habits leading to thin stools. It may also cause mucous in your stools, which can gives stool a stringy appearance.

Some intestinal infections such as salmonella, gastroenteritis, and shigella may cause loose stools or diarrhea.

Stringy stool may also occur for no obvious reason.

There’s no reason to call your doctor if you have occasional stringy stool. If it happens for more than a week, or you also have vomiting, fever, abdominal pain, or rectal bleeding, you still should call your doctor. They will discuss your symptoms and determine if tests or treatment are needed.

Tests to determine the cause of stringy poop may include:

  • fecal occult test to check for blood in your stool
  • stool sample test to check for the presence of parasites or bacteria
  • blood tests to rule out celiac disease
  • flexible sigmoidoscopy to examine your lower colon
  • colonoscopy to examine your entire colon
  • x-ray with contrast (barium) to view your gastrointestinal tract
  • CT scan to view your abdominal organs

The treatment plan for stringy stool depends on the cause. If it only happens once in a while, you will likely not need any treatment.

Constipation

If the stringy stool is caused by constipation, drinking plenty of water and eating more fiber-rich foods should help. Some fiber-rich foods are:

  • bran
  • legumes
  • seeds
  • fresh fruits and vegetables

If necessary, you may also take a fiber supplement.

Need help choosing a fiber supplement: What’s the best fiber supplement? »

Celiac disease

When stringy stool is caused by celiac disease, eliminating all products containing gluten from your diet helps keep it under control.

Parasite or infection

If stringy poop is caused by a parasite or other infection, you may need medication to clear it up. Most parasites are treated with anti-parasitic drugs. Some are eliminated in one treatment while others require treatment for several weeks.

You shouldn’t use herbal remedies to treat parasites unless advised by your doctor. Herbal remedies are potent and may be dangerous if used incorrectly.

Intestinal infections

Salmonella and other intestinal infections often clear up on their own in several days. In severe cases, your doctor may prescribe antibiotics or antidiarrheal medications. It’s also important to drink plenty of water to replenish fluids lost due to vomiting and diarrhea.

Colorectal cancer

Treatment for colorectal cancer depends on the stage. Early-stage cancer may be resolved with minimally invasive surgery. Invasive colorectal cancer may be treated by removing part of the colon and the surrounding lymph nodes. Chemotherapy, radiation therapy, and targeted drug therapy may also be used.

Additional treatments

When the cause of stringy poop is serious, such as a bowel obstruction or hernia, you’ll need urgent care. A combination of surgery and medication may be needed.

Most people experience stringy poop at least once. In most cases, the outlook is good. When the condition is sporadic and you do not have other symptoms, it’s likely nothing to worry about and should resolve on its own within a short time.

When stringy poop is caused by a serious condition, your outlook depends on how quickly you receive care and the extent of the damage. In many cases, dietary changes, medication, surgery, and good aftercare successfully resolves symptoms.

When it comes to poop, the important thing is for you to know what is normal for you. If you’ve never had stringy poop before and suddenly have it regularly, contact your doctor.

Q:

Should I take a daily fiber supplement?

A:

Experts recommend 25-35 grams of fiber per day. You can get this amount of fiber from your normal diet with or without supplements. Make sure that you’re eating soluble fiber instead of insoluble fiber, or you may experience constipation. Consuming too much fiber in your diet and not drinking enough caffeine-free beverages can also lead to constipation.

Increasing your daily fiber intake can cause abdominal bloating, excessive gas, and diarrhea. These symptoms usually resolve once your body adjusts to your new diet. You should increase your fiber intake by about 5 grams per week until you reach your target level. 

Graham Rogers, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.