What Causes Hard, Small, and Pellet-Like Stool

Not Eating Enough Fiber

The size of your stool is directly related to the amount of fiber and water you consume. Found in plant-based foods including vegetables, fruits, and whole grains, fiber adds bulk to your stool and is fermented by bacteria in your colon, forming a gel that keeps poop from breaking apart in pieces.

If you get enough fiber in your diet, your stool should be soft, easy to pass, and formed. If your diet is low in fiber, your body makes a smaller amount of stool and it may be difficult to pass, hard, dark, or fragmented in tiny pieces.

On average, adults consume 15 grams or less of fiber a day, far less than the recommended amount. According to the Institute of Medicine, the recommended daily intake is 38 grams of fiber for men and 25 grams for women under the age of 50. If you're over 50, the recommended intake is 30 grams for men and 21 grams for women.

If you're not sure how much fiber you're getting, try keeping a food diary for a week. If you eat less than the recommended amount, upping your fiber intake may improve the frequency and consistency of your stool. Here are some fiber-rich foods to try:

Lentils (15.6 grams per cup)
Raspberries (8 grams per cup, raw)
Green peas (7 grams per cup)
Avocados (7.8 grams per half-cup)
Chia seeds (5.5 grams per tablespoon)
Oatmeal (4 grams per cup, cooked)
Almonds (3.3 grams in 24)
Ground flaxseeds (1.9 grams per tablespoon)

Increase your intake of fiber gradually to avoid bloating and gas.

Not Drinking Enough Fluids

Fiber and water work together to make your stool easy to pass. If you aren't getting enough fluids, water in your intestines is absorbed into your system, making stool small, hard, and difficult to pass.

When it comes to hydrating, many health care professionals advise that healthy people use thirst as their guide and look for varied sources of water such as fruits, vegetables, herbal teas, juices, soups, and other beverages.

If you aren't sure how much water is right for you, ask your healthcare provider. Depending on factors like age, body weight, and medical conditions, some people may need to drink more and some people may need less than the recommended intake.

Medication

Medication that can result in constipation in some people include:

Antacids
Antidepressants
Calcium channel blockers
Diuretics
Iron supplements
Narcotic pain medication
Parkinson's disease medication

Lifestyle

Spending hours at your desk hunched over your keyboard or leading a sedentary lifestyle can slow digestion. To combat prolonged sitting and physical inactivity, get up and move around or take a brief walk every hour.

Regular gentle exercise helps to improve the movement of stool through the digestive tract. As a general goal, strive for at least 30 minutes of physical activity most days.

Make time to go to the bathroom when you feel the urge. Ignoring the urge can worsen constipation. You can try getting up a bit earlier to eat breakfast, which can encourage bowel movements. Avoid pushing or straining when you're on the toilet.

Certain Health Conditions

Although small stool is often the result of a lack of fiber or fluids, in some cases, it may be a sign of an underlying medical problem. Some medical causes of constipation include:

Hypothyroidism
Inflammatory bowel disease
Depression
Diabetes
Irritable bowel syndrome (IBS)
Multiple sclerosis
Parkinson's disease
Uterine fibroids
Cancer

A small number of people with constipation or thin stools have an underlying condition that compresses or narrows the colon or rectum, such as colon polyps, diverticulitis, inflammatory bowel disease, or colon cancer.

When to See Your Doctor

Having small stools from time to time is usually nothing to worry about. If you notice that your small stools last longer than one to two weeks, however, or are accompanied by other symptoms, you should consult your doctor.

If you have nausea, vomiting, or abdominal pain and haven't been able to pass stools, you should seek medical attention immediately.

A Word From Verywell

Passing poop that looks like nuggets, small pieces, rabbit pellets, or balls from time to time is usually normal. If your diet is the culprit, eating more fiber-rich foods and staying hydrated can often help you get back on track, although it may take a few days before you notice an improvement. If you're considering making any diet or lifestyle changes, speak to your doctor before making any major changes to your routine.

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Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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Additional Reading

Institute of Medicine. 2005. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press. doi:https://doi.org/10.17226/10490.
National Digestive Diseases Information Clearinghouse. Constipation. https://www.niddk.nih.gov/health-information/digestive-diseases/constipation.
US Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference, Release 28.