Causes of Changes in Stool Size

Have you noticed that your stool size is not normal and feel concerned about it? Continue reading this article to learn about the causes of changes in stool size, which can range from minor reasons to serious conditions that require medical treatment.

What Causes Changes in Stool Size?

Changes in stool size, whether it appears smaller or larger than usual, can result from various factors. Here are some detailed explanations:

• Causes of Thin Stool

There are several reasons why stool may consistently appear thin and elongated, including:

1. Constipation

The primary reason behind changes in stool size, making it appear thin, is constipation. This condition may occur due to a low-fiber diet, as fiber adds bulk to stool. Without sufficient fiber, stool may lose its bulk and become thin or stringy. 

Other causes of constipation include low fluid intake, lack of exercise, pregnancy, travel, certain medications, or hormonal changes.

2. Hemorrhoids

Another reason for changes in stool size, resulting in thin stool, is internal hemorrhoids. These are inflamed and swollen veins in the rectum or anus, which can cause stool to appear thin when passing. They may also cause rectal bleeding visible in the stool.

3. Irritable Bowel Syndrome (IBS)

IBS can cause changes in stool size or shape, making it appear smaller or very thin, particularly in constipation-dominant IBS. Stress and anxiety can exacerbate IBS symptoms in affected individuals.

4. Certain Medications

Medications that slow bowel movements can lead to thin stool. Examples include:

• Opioid pain relievers, such as morphine.
• Anticholinergic drugs, like scopolamine.
• Anti-diarrheal medications when used frequently.

5. Anal Cancer 

A rare cause of changes in stool size is anal cancer, a rare type of cancer starting in the anus or the outer part of the rectum, where stool exits. This cancer is rare but may increase with HPV infection and presents symptoms like:

• Pain, bleeding, and itching in the rectum.
• Strange rectal discharge.
• Lumps around the opening of anus.
• Swollen lymph nodes around the anus.

6. Colorectal Cancer

A gradual narrowing of stool size can be a symptom of colorectal cancer, though it usually results from less serious conditions. If a cancerous mass is large enough to obstruct stool movement through the intestines, thin stool may be the only thing that can pass. Other symptoms include:

• Changes in bowel habits, alternating between diarrhea and constipation.
• Anemia.
• Abdominal pain and bloating.
• Unexplained weight loss.
• Blood in the stool.

7. Diverticulitis

This digestive condition involves inflamed or infected pouches in the colon or large intestine. In severe cases, it can cause very thin or pellet-like stool.

8. Fecal Impaction

This occurs when a mass of dry stool gets stuck in the rectum, blocking other stool from passing normally, leading to the passage of small, ribbon-like stool.

• Causes of Large Stool

Several factors can cause an individual to produce larger-than-normal stool, such as:

1. Dehydration and constipation.
2. Consuming large meals or following a high-fiber diet.
3. Digestive disorders, such as IBS, Crohn's disease, or ulcerative colitis.
4. Fecal incontinence (Encopresis).
5. Long-term use of laxatives.
6. Megacolon, a complication of chronic constipation, bowel obstruction, or inflammatory bowel disease.

What is the Normal Stool Size?

Normally, stool length ranges from 10 - 20 centimeters, with a diameter of 2.5 - 5 centimeters. If stool is consistently thin and very long, like a pencil or ribbon, or consistently very large, it is important to consult a doctor to determine the cause.

How are Changes in Stool Size Diagnosed?

A doctor may recommend several tests to accurately determine the causes of changes in stool size, including:

• Digital rectal examination.
• Stool tests.
• Complete blood count.
• Imaging tests, such as X-rays or ultrasound.
• Endoscopy and colonoscopy.

Blazma provides various tests your doctor might request, such as stool analysis, occult blood test, and stool culture and sensitivity tests, which do not require prior preparations other than informing your doctor about any medications you are taking.

When Should You See a Doctor?

If stool continues to appear thinner or larger than usual for more than two weeks, or if it consistently becomes thinner and resembles a pencil, you should see a doctor immediately. Also, seek medical attention if changes in stool size are accompanied by:

• Unexplained weight loss.
• Bloody stool.
• A feeling of a lump in the rectum.
• Abdominal pain and bloating.

By understanding the potential causes and taking appropriate steps, you can ensure your digestive health and well-being.