Anyone can occasionally have narrow stools.
Rarely, they are indicative of serious causes such as colon or rectal cancer.
Catherine McQueen / Getty Images
What Are Narrow Stools?
Catherine McQueen / Getty Images
Narrow stools are pencil-thin (stringy) and canbe flatinstead of rounded.
Sometimes, they happen without any known cause.
When skinny stools happen frequently, the causes may range fromconstipationto something more serious like cancer.
Constipation
Having thin stools, or pooping small pieces, can signal constipation.
When you are “backed up,” stool passes slowly through the intestines.
This allows the intestines to absorb more water from the stool, making it even more difficult to pass.
If there is significant constipation, only thin amounts of stool may be able to pass through.
Signs of constipation include:
Treatment:Increasing fiber in the diet is important fortreating constipation.
Staying well-hydrated can also help.
Medications may be necessary for those whose stools dont improve enough through dietary changes or drinking extra water.
These can include:
2.
Hemorrhoids
Internal hemorrhoidsare swollen and inflamed veins in the rectum or anus that don’t extend outside the body.
If they are large, they can force stool into a narrow shape as it exits.
Internal hemorrhoids may also cause rectal bleeding, which may be present in or on poop.
These stools will also likely be very soft in consistency.
However, more severe cases may require medical treatment, such as IV fluid replacement.
Medications
Medications that slow the movement of the intestines can cause narrow stools.
They can lead to constipation and possible fecal impaction, causing thin stool.
They may be able to change the dose or prescribe a different drug.
Irritable Bowel Syndrome (IBS)
IBS can cause changes in the size and shape of your stool.
It’s common for people with IBS to have stool that is smaller or narrower, especially inconstipation-predominant IBS.
In some cases, medication may be required.
These could include:
Research suggests that stress and anxiety may worsen IBS symptoms.
If you’re having trouble managing your stress or anxiety, talk with your healthcare provider.
Other symptoms associated withcolon cancerinclude:
Treatment:Colorectal cancertreatments vary depending on how advanced the cancer has become.
Anal Cancer
Anal cancer can have many of the same symptoms as colorectal cancer, including narrow stools.
This key in of cancer begins in the cells around or inside the opening of the anus.
Diverticulitis
Diverticulitisis a digestive condition in which inflamed or infected pockets form in the large intestine (colon).
People with an advanced case may have narrow stools or very small stools shaped like pellets.
When the condition causes the lower colon to become distorted, it can change the shape of your stool.
Cases of diverticulitis likely to cause narrow stool typically need additional treatment.
Some people with diverticulitis develop complications such as an abscess, intestinal obstruction, fistula, or abdominal infection.
In these cases, additional procedures and medications are necessary.
Fecal Impaction
Fecal impactionis similar to constipation but more significant.
This blocks the ability of other waste to move through normally.
Only narrow stool may be able to pass.
Treatment:Fecal impaction is treated by removing the stuck stool in the rectum.
A healthcare provider can do this manually.
Interventions such assuppositoriesorenemasmay also be used.
Rarely surgical intervention is necessary.
Treatment: Interventions include conservative treatment options such as hydration, increasing fiber, and bulk-forming laxatives.
In severe cases, surgical intervention is often necessary.
Infections
Various infections from bacteria, viruses, andparasitescan cause loose and narrower stools.
Examples include:
Treatment:Treatment for infections depends on the underlying cause.
Many viruses are treated with supportive care, such as hydration and rest.
Bacterial infections may require antibiotics, and parasites may require antiparasitic medication.
What Is a Normal Stool Supposed to Look Like?
It should be brown, soft, and not difficult to pass.
It is typically smooth instead of lumpy and may resemble a sausage.
It is also normal for stool to appear like soft blobs with defined edges.
Persistent Changes
The occasional episode of thin stool is likely not a cause for concern.
If you have risk factors for colon cancer, contact your healthcare provider if you experience narrow stools.
Diagnostics
A healthcare provider may recommend tests to help determine the cause of thin stools.
Contact your healthcare provider for advice regarding persistently narrow stools.
Tests can help find the underlying cause.
Panda H, Andrews CN.Constipation in a 40-year-old woman.CMAJ.
2016;188(4):277-278.
National Institute of Diabetes and Digestive and Kidney Disease.Symptoms & causes of constipation.
American Society of Colon and Rectal Surgeons.Hemorrhoids.
2017;93(4):320-327.
National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of irritable bowel syndrome.
UpToDate.Patient education: Irritable bowel syndrome (Beyond the Basics).
Centers for Disease Control and Prevention.Symptoms of colorectal cancer.
National Library of Medicine.Colorectal cancer.
American Cancer Society.Signs and symptoms of anal cancer.
Coakley KM, Davis BR, Kasten KR.Complicated diverticular disease.Clin Colon Rectal Surg.
2021;34(2):96-103. doi:10.1055/s-0040-1716701
MedlinePlus.Fecal impaction.
National Library of Medicine.Fecal impaction.
National Institute of Diabetes and Digestive and Kidney Diseases.Symptoms & causes of diarrhea.
2016;44(7):693-703.
2020;12(2):298.
American Cancer Society.Colorectal cancer signs and symptoms.
World Health Organization.Colorectal cancer.
