Overview
Narrow stools, also known as thin stools, can be a concerning symptom, especially when accompanied by other digestive issues like gas or changes in bowel habits. While stringy stools can sometimes result from minor dietary changes or temporary intestinal issues, they can also be an early sign of more serious conditions like irritable bowel syndrome (IBS) or even colon cancer. In particular, many patients worry about the connection between colon cancer and pencil-thin stools, as this symptom is often associated with the narrowing of the colon due to tumor growth. Understanding the causes of thin stools and when to seek medical advice is crucial for early detection and effective treatment.
This article explores common causes of thin stools, such as IBS and other gastrointestinal issues, and discusses the potential link between thin stools and colon cancer, supported by scientific evidence. Additionally, we’ll provide insights into treatment options to help alleviate symptoms and improve digestive health.
Have you been experiencing narrow stools lately? Review the symptoms below:
Narrow stools,nausea and abdominal pain
Can indicate a parasitic infection.
Foul-smelling stools with changes to stool consistence.
Can indicate malabsorption such as steatorrhea and celiac disease or an infection.
Diarrhea, constipation, abdominal pain and fatigue.
These symptoms can indicate conditions such as IBD and IBS .
What are narrow stools, and what do they mean for your digestive health?
Thin or narrow stools are characterized by a significantly smaller diameter than regular bowel movements, often resembling “pencil-thin” shapes. Usually, stools are well-formed, cylindrical, and measure around 2.5 to 4 cm (1 to 1.5 inches) in diameter, indicating a healthy digestive system. When stools consistently measure less than 1.25 cm (0.5 inches) in diameter, this size reduction may signal an underlying issue in the gastrointestinal tract, such as narrowing or obstruction. The appearance of thin stools can be continuous or intermittent, and their consistency may vary based on several factors.
Stool Type Diagnosis
| Stool Type | Appearance | Associated Symptoms | When to Consult a Doctor | Image | Action |
|---|---|---|---|---|---|
| Normal | Well-formed, cylindrical, brown, 2.5-4 cm diameter | Healthy digestion, regular bowel movements | No concerns unless there is an unexplained change |  | Consult Now |
| Thin/Narrow | Pencil-thin, less than 1.25 cm in diameter | Abdominal pain, bloating, changes in bowel habits | Consult if persistent, especially with pain or weight loss |  | Consult Now |
| Hard/Pellet-like | Small, hard lumps, difficult to pass | Constipation, straining, fewer than 3 movements/week | If constipation persists despite treatment |  | Consult Now |
| Loose/Watery | Loose, watery stools | Diarrhea, abdominal cramping | Consult if lasting more than a few days or with dehydration |  | Consult Now |
| Greasy/Floating | Oily, floating stools | Malabsorption, bloating | Consult if persistent, could indicate malabsorption |  | Consult Now |
Stool Type Diagnosis
| Normal | |
|---|---|
 | |
| Appearance | Well-formed, cylindrical, brown, 2.5-4 cm diameter |
| Associated Symptoms | Healthy digestion, regular bowel movements |
| When to Consult a Doctor | No concerns unless there is an unexplained change |
| Thin/Narrow | |
|---|---|
 | |
| Appearance | Pencil-thin, less than 1.25 cm in diameter |
| Associated Symptoms | Abdominal pain, bloating, changes in bowel habits |
| When to Consult a Doctor | Consult if persistent, especially with pain or weight loss |
| Hard/Pellet-like | |
|---|---|
 | |
| Appearance | Small, hard lumps, difficult to pass |
| Associated Symptoms | Constipation, straining, fewer than 3 movements/week |
| When to Consult a Doctor | If constipation persists despite treatment |
| Loose/Watery | |
|---|---|
 | |
| Appearance | Loose, watery stools |
| Associated Symptoms | Diarrhea, abdominal cramping |
| When to Consult a Doctor | Consult if lasting more than a few days or with dehydration |
| Greasy/Floating | |
|---|---|
 | |
| Appearance | Oily, floating stools |
| Associated Symptoms | Malabsorption, bloating |
| When to Consult a Doctor | Consult if persistent, could indicate malabsorption |
Symptoms of Narrow Stools: Warning signs you shouldn’t ignore
Low-diameter stools, or pencil-thin stools, can indicate various digestive issues. Here’s a concise overview of potential symptoms and their causes:
Consistently Thin Stools
Consistently Narrow diameter stools may signal changes in bowel motility or intestinal obstructions, such as those caused by IBS or tumors.
Change in Bowel Habits
Frequent changes between diarrhea and constipation, along with narrow thin stools, could indicate conditions like irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD).
Abdominal Pain or Discomfort
Abdominal cramping or pain, varying in intensity, often accompanies narrow pencil stools in cases of IBS, diverticulitis, or bowel obstruction.
Visible Blood in Stool
Blood in the stool, whether dark and tarry or bright red, may indicate hemorrhoids or more severe issues like colorectal cancer.
Bloating and Gas
A sensation of fullness or excessive gas with narrow stools can be due to disrupted digestion, as seen in IBS or partial intestinal blockages.
Sensation of Incomplete Evacuation
Feeling like bowel movements are incomplete is common with IBS or rectal strictures, where bowel function is compromised.
Unexplained Weight Loss
Unintended weight loss, combined with narrow stools, can be a sign of serious conditions like colorectal cancer, affecting nutrient absorption.
Fatigue
Persistent fatigue often results from chronic digestive conditions like cancer or severe inflammation due to nutrient deficiencies or anemia.
Nausea and Vomiting
Nausea and vomiting, alongside thin stools, may indicate a partial intestinal blockage or severe gastrointestinal disease.
Mucus in Stool
Mucus in the stool is a sign of inflammation or infection in the intestines, commonly seen in IBS, IBD, or intestinal infections.
Why am I passing skinny or thin stools? Causes explained
“While occasional narrow stools may not always indicate a serious issue, persistent or recurring thin stools should never be ignored, especially if accompanied by symptoms like abdominal pain, unexplained weight loss, or blood in the stool. These signs could point to underlying conditions like irritable bowel syndrome or, in some cases, colorectal cancer.”
Passing skinny stools can be concerning, but it’s essential to understand that occasional changes in stool shape may not always signal a serious problem. However, frequent occurrences of narrow stools could indicate underlying health conditions that require medical attention. Below are scientifically backed reasons for skinny stools, their symptoms, and when to consult a healthcare professional.
Intestinal Infection
Intestinal infections, such as gastroenteritis, can cause inflammation in the intestines, leading to altered bowel movements, including thin or thin skinny stools. Infections may result from bacteria, viruses, or parasites and typically present with other symptoms like diarrhea, abdominal pain, and fever.
Gastrointestinal parasite infections
Parasites like roundworms or other gastrointestinal parasites can disrupt regular bowel movements, causing narrow stools or diarrhea. These parasites often enter the body through contaminated food or water and thrive in the intestines, causing digestive disturbances.
Constipation
Constipation is a common cause of thin stools, resulting from slow-moving stool that hardens and becomes difficult to pass. This can lead to narrow, skinny stools squeezing through a partially blocked colon. Signs include fewer than three weekly bowel movements, hard stools, and difficulty passing them. Chronic constipation and fecal impaction may also cause severe complications if untreated.
Hemorrhoids
Internal hemorrhoids, which are swollen veins in the rectum or anus, can narrow the passage through which stool passes, leading to thinner stools. Hemorrhoids may also cause rectal bleeding, pain, and discomfort during bowel movements.
Irritable Bowel Syndrome (IBS)
IBS, particularly constipation-predominant IBS, can lead to changes in stool shape and size, including narrow stools. IBS is often triggered by stress and can cause additional symptoms such as bloating, abdominal pain, gas, and mucus in the stool. A systematic review of IBS and its associated risks indicates that while IBS is a common cause of changes in stool consistency, including narrow stools, it is not directly linked to an increased risk of colorectal cancer.
Colorectal Cancer
One of the more severe causes of narrow stools is colorectal cancer. A mass or tumor in the colon can block or constrict the intestinal passage, leading to thin stools. Other symptoms include blood in the stool, abdominal pain, unexplained weight loss, fatigue, and changes in bowel habits. Early screening and diagnosis are crucial for successful treatment.
Anal Cancer
Like colorectal cancer, anal cancer can also result in narrow stools. It originates in or around the anus and may present with additional symptoms like rectal bleeding, anal itching, and a lump near the anus. HPV infection is a known risk factor for anal cancer.
Diverticulitis
Diverticulitis involves the inflammation or infection of small pouches (diverticula) that form in the walls of the colon. These pouches can distort the intestinal tract, leading to reduced-diameter stools. Symptoms of diverticulitis include abdominal pain, changes in bowel habits, blood in the stool, and bloating.
Fecal Impaction
Severe constipation, or fecal impaction, occurs when a lump of dry stool becomes lodged in the rectum, blocking the passage of other waste. This can cause thin stools to pass around the obstruction. Symptoms of fecal impaction include abdominal discomfort, bloating, and difficulty passing stools.
Crohn’s Disease and Ulcerative Colitis
Inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis can cause changes in stool consistency, frequency, and appearance. Narrow stools may result from intestinal inflammation, affecting the normal waste passage through the digestive system.
Twisted Bowel (Volvulus)
A twisted bowel, or volvulus, occurs when a loop of the intestine twists around itself, obstructing the gut. This condition can lead to severe pain, bloating, and thin stools. If left untreated, volvulus can cause serious complications, requiring immediate medical intervention.
Read More: White Specks In Your Poop: Causes, Treatment and Complications
What are the risk factors of stringy poop?
- Age
- A family history of the condition
- Personal history of inflammatory bowel disease
- A diet rich in red or processed meat
- A sedentary lifestyle is a risk factor for colorectal cancer
- A history of abdominal surgery, particular drugs, and specific medical diseases like Crohn’s Disease are risk factors for intestinal blockage.
How to diagnose pencil poop?
Suppose you frequently see changes in the appearance of the stool, or it may be narrower than usual. In that case, your doctor can refer you to a rectal or colon specialist who can suggest various tests to diagnose the disease. Doctors recommend several methods.
Fecal Occult Test
A fecal occult test (FOBT) is to find hidden blood in stool samples. Additionally, this test checks for colorectal cancer and other gastrointestinal conditions that may result in gastrointestinal bleeding. Moreover, the FOBT test takes a tiny feces sample and checks in a lab to identify whether blood is present. The guaiac-based FOBT (gFOBT) and the fecal immunochemical test are the two types of FOBT assays (FIT). To detect the presence of blood in the stool, the gFOBT test uses a chemical called guaiac, which turns blue with the sample.
Stool Sample Test
A doctor can also recommend doing a stool sample examination for infections. Using a stool culture, the doctor can check whether the intestines have bacterial contamination.
Little stool samples are collected by a technician in sterile plastic dishes with nutrients that promote the growth of particular bacteria. Growth will occur only if the targeted bacteria are already in the stool sample.
Blood tests to detect infection
The process of a blood test is simple and familiar. Lab attendants examine particular biomarkers that analyze the blood changed composition. When inflammatory bowel disease is present, a blood test will show an increased white blood cell count, which could indicate inflammation.
Imaging tests
The following tests are essential to get the correct diagnosis
- CT Scan
- Ultrasounds
- X-ray imaging of your abdomen and pelvis
The doctor may occasionally use a CT scan or X-ray to obtain a better image of the colon and rectum. These examinations can reveal further information regarding the internal structure of the organs and other abnormalities.
Endoscopy or colonoscopy
Medical techniques like endoscopy and colonoscopy can help identify the root cause of thin stools. In these procedures, a doctor may insert a long, flexible tube with a camera at one end into the colon and rectum to check their linings.
When a patient experiences thin stools, the doctor may detect a constriction or obstruction in the colon or rectum. In addition, you can use endoscopy or colonoscopy to find the position and size of any blockage.
The doctor may do a biopsy, which comprises collecting a microscopic tissue sample for analysis if an obstruction is found. It can help determine whether a tumor, scar tissue, or inflammation is the cause of the block.
Flexible Sigmoidoscopy
Flexible sigmoidoscopy is another medical diagnostic procedure to find the cause of narrow stools. Like a colonoscopy, this operation focuses on inspecting only the rectum and the bottom part of the colon, called the sigmoid colon.
During a flexible sigmoidoscopy, a doctor inserts a flexible tube with a camera on its end into the rectum and sigmoid colon. Also, they are making it possible for the doctor to identify any irregularities, including inflammation, polyps, or tumors, on the lining of these organs.
How to treat narrow stools?
Prescription Medications
- Prescription Laxatives:
- Examples: Lactulose, linaclotide (Linzess), and lubiprostone (Amitiza).
- Usage: Used for chronic constipation not relieved by OTC medications.
- Anticholinergic Medications:
- Examples: Dicyclomine (Bentyl) and hyoscyamine (Levsin).
- Usage: Used for managing IBS symptoms by reducing intestinal spasms.
- Pain Medications:
- Examples: Low-dose tricyclic antidepressants like amitriptyline (Elavil).
- Usage: Used for their pain-relieving properties in IBS.
- Antibiotics:
- Examples: Rifaximin (Xifaxan).
- Usage: Used for bacterial overgrowth in the intestines that can cause IBS symptoms.
- Medications for Hemorrhoids:
- Examples: Prescription-strength hydrocortisone cream suppositories.
- Usage: Reduce inflammation and swelling in hemorrhoids that may cause narrow stools.
- Medications for Colorectal Conditions:
- Examples: Chemotherapy drugs for colorectal cancer and anti-inflammatory medications for inflammatory bowel disease (IBD).
- Usage: Treat underlying conditions that cause narrow stools.
Over-the-counter (OTC) Medications
- Laxatives:
- Bulk-forming Laxatives:
- Examples: Psyllium (Metamucil) and methylcellulose (Citrucel).
- Usage: Add bulk to stools and make them easier to pass.
- Stimulant Laxatives:
- Examples: Bisacodyl (Dulcolax) and senna (Senokot).
- Usage: Stimulate bowel movements.
- Osmotic Laxatives:
- Examples: Polyethylene glycol (MiraLAX) lactulose.
- Usage: Draw water into the intestines to soften stools.
- Bulk-forming Laxatives:
- Stool Softeners:
- Examples: Docusate sodium (Colace).
- Usage: Help stools retain water, making them softer and easier to pass.
- Fiber Supplements:
- Examples: Psyllium (Metamucil) and methylcellulose (Citrucel).
- Usage: Add bulk to stools, making them easier to pass.
- Suppositories and Enemas:
- Examples: Glycerin suppositories and saline enemas.
- Usage: Stimulate bowel movements in cases of severe constipation or fecal impaction.
How to Get Your Stool Back to Normal with Home Remedies?
Some of the home remedies to get your stool back to normal are as follows
- Increase Fiber: To improve stool bulk, aim for 25–30 grams daily of fiber from fruits, vegetables, and whole grains.
- Stay Hydrated: Drink 8 glasses of water daily to prevent hard, narrow stools.
- Exercise: Regular physical activity (30 minutes daily) promotes healthy bowel movements.
- Avoid Straining: Maintain proper posture on the toilet to aid natural bowel function.
- Probiotics: Include probiotics from foods like yogurt or supplements to support gut health.
Read More: Poop Looks Like Coffee Grounds – Causes and Treatments
When to Consult a Doctor
If narrow stools persist for more than a few days or are accompanied by additional symptoms such as blood in the stool, abdominal discomfort, or sudden weight loss, it’s essential to consult your doctor. These symptoms can indicate serious conditions like colon cancer, and early detection is critical for effective treatment.
FAQS about Narrow Stools Answered by Your Doctor Online
Several medications can contribute to thin stools by slowing down intestinal movement. Common culprits include opioid pain relievers like morphine and hydrocodone, anticholinergics such as scopolamine and oxybutynin, and overused antidiarrheal medications like loperamide (Imodium), which can cause constipation and thin stools if taken for extended periods.
A normal stool is typically medium to dark brown, indicating a healthy digestive process. It should be smooth, soft, and sausage-like, reflecting adequate fibre and water intake. Normal stool should pass easily without straining and be moderately sized and consistent. It should neither be too hard nor too runny, falling between the extremes of constipation and diarrhea. Regular bowel movements, typically ranging from three times a day to three times a week, are also a sign of normal stool.
A healthy bowel movement is usually brown, smooth, and soft in texture and is formed into a sausage or snake-like shape. It should be easy to pass without straining and not too hard or loose. Frequency can vary, but regularity is critical, ranging from a few times a day to a few times a week for most people.
Indeed, anxiety and stress can lead to thin stools. This is due to the robust link between your stomach and brain, often known as the gut-brain axis. Your body releases stress-related hormones like cortisol and adrenaline, which can affect digestion and cause diarrhea or loose stools. Thus, experiencing a thin stool may be a legitimate reaction to anxiety.
Yes, when polyps get bigger, they can occasionally cause the stool to get narrower. Unusual tissue growths called polyps can form in the rectum and colon (large intestine). They may partially clog the colon, causing variations in the size and form of the stool, depending on their position and size. Though many are found during standard screening before they produce any discernible changes in bowel habits, not all polyps cause symptoms. You must consult your healthcare physician if you have any concerns regarding your stool or the possibility of polyps.
Various factors, including a diet rich in green vegetables or foods with green colouring, can cause green poop. Rapid transit through the digestive tract can also lead to greenish stool, as bile doesn’t break down completely. Infections causing diarrhea may result in green stool, as can certain medications or supplements. While usually harmless, green stool can sometimes indicate underlying issues like malabsorption or bacterial infections.
Gas and thin stools might have several causes. Dietary practices are essential; a diet heavy in items that produce gas or poor in fibre may cause these symptoms. Changes in stool consistency and increased gas can also be caused by digestive problems such as gastrointestinal infections or irritable bowel syndrome (IBS). Furthermore, some drugs can interfere with digestion, producing gas and weak stools. But occasionally, these signs could point to more serious underlying illnesses, including inflammatory bowel disease (IBD) or colon cancer.
No, thin, long, skinny poop or stools don’t always mean cancer and are often caused by factors like a low-fibre diet, temporary infections, or irritable bowel syndrome (IBS). But if the thin narrow stools don’t go away after a week or come with other symptoms like blood in the stool, stomach pain, vomiting, or unexplained weight loss, those could be signs of a more severe illness like anal or colorectal cancer. See a doctor for a diagnosis if you experience any of these symptoms, as early detection and treatment are crucial for successful cancer treatment.
Diverticulitis can cause changes in stool without indicating a specific colour. Watch for thin or pellet-like shapes due to colon narrowing, and be alert for bright red, maroon, or black stools, which can signal bleeding. The condition can also cause diarrhea or constipation, affecting consistency, and you might notice more mucus in your stool. Additionally, changes in frequency or an increased foul odour could be signs of diverticulitis.
Long poop can result from various factors, including a diet high in fibre, which promotes healthy digestion and bulkier stools. It can also be due to good hydration, which helps soften stools and allows them to pass more quickly. However, it could be a good idea to see a doctor to rule out any underlying issues if other symptoms like discomfort, pain or changes in bowel habits accompany the length of your stool.
Unhealthy stools may appear hard and pellet-like (constipation), loose and watery (diarrhea), or narrow and ribbon-like (obstruction). Abnormal colors like black, red, or pale stools can indicate bleeding or liver issues. Greasy or floating stools suggest malabsorption, while the presence of mucus may signal inflammation. Significant changes in stool shape, color, or frequency warrant medical attention.
