What's this test for?

This test is ideal if you're experiencing ongoing or unexplained diarrhea and need to understand what's causing it. It measures the concentration of dissolved particles in a liquid stool sample, which helps figure out whether your diarrhea is related to something you're eating or drinking versus a digestive process that's pulling extra water into your gut. It's often used alongside other stool tests to narrow down the cause of persistent digestive symptoms.

What's included in this test?

This test includes a single measurement: stool osmolality, which reflects the total concentration of dissolved substances in your liquid stool sample. This one value matters because it helps distinguish between diarrhea caused by something in your diet or gut absorption versus diarrhea caused by an infection or inflammation pulling fluid into the intestines.

What happens after I get my results?

Your results will show up in your account along with the normal range so you can see exactly where your number falls. If your osmolality reading is unusual, simple next steps include reviewing your recent diet and fluid intake, since certain drinks and foods can skew the result, and considering a repeat test if symptoms continue. Your full lab report is available to download from your account at any time, and you can use the trends feature to track changes if you test again in the future. If your diarrhea is severe, persistent, or paired with signs of dehydration, seek medical care right away.

When will I get my results?

Results are typically ready within about 7 days of your sample being received at the lab. Once processing is complete, you'll be able to view and download your report directly from your account. You'll get a notification as soon as your results are available.

Who should consider this test?

This test is a good fit for anyone dealing with chronic or recurring watery diarrhea that hasn't been explained by other testing. It's also useful if you and previous test results suggest the need to sort out whether your diarrhea is linked to diet, medication, or a digestive absorption issue. This test is typically ordered as part of a broader diarrhea work-up rather than as a standalone screening.

What symptoms indicate I may need this test?

Watery or loose stools that last more than a few days, unexplained weight loss, or diarrhea that doesn't improve with typical dietary changes are common reasons to consider this test. Bloating, cramping, and stool that seems unusually watery can also point to the need for this kind of testing. If symptoms are severe or you notice signs of dehydration, seek medical care promptly.

How can I naturally support healthy digestion?

Staying well-hydrated with water and electrolyte drinks can help your gut recover while you sort out the cause of diarrhea. Eating bland, easy-to-digest foods like rice, bananas, and toast can ease symptoms in the short term. Cutting back on sugar alcohols, artificial sweeteners, and excess caffeine can also reduce osmotic-type diarrhea since these substances pull extra water into the gut.

What is stool osmolality and why does it matter?

Stool osmolality is a measure of how concentrated your liquid stool sample is with dissolved particles. It matters because comparing this number to your stool's sodium and potassium levels helps identify whether diarrhea is being caused by osmotic factors, like certain sugars or laxatives pulling water into the gut, or by other causes such as infection or inflammation.

What causes abnormal stool osmolality results?

Diluting a stool sample with water, recent use of laxatives, or drinking large amounts of certain sugary or artificially sweetened beverages can all affect this result. Bacterial activity in the sample after it's collected can also raise the reading over time, which is why quick processing matters. Certain digestive conditions that affect how your gut absorbs nutrients and fluids can shift the number as well.

How often should I retest?

If your diarrhea resolves after this test, there's usually no need to retest. If symptoms continue or change, retesting alongside other stool studies every few weeks can help track whether the underlying cause is improving. Ongoing or worsening symptoms are a signal to seek medical care rather than relying on repeat home testing alone.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

How do I know which test to get?

In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option. Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.

When will my lab results be available?

Most test results will be available within 1–3 business days. Once they're ready, we'll send an email and text message to let you know. After your blood draw, just hang tight and don't worry – we'll keep you updated and in the loop! If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com, and we'll gladly help you.

Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

Absolutely! We totally understand that errors can happen. No worries, we're here to help you. Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you. There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out. Our lab requires an address to be listed to generate an order.

Do you accept health insurance?

Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

Can I cancel my order?

Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

Stool Osmolality Test - Diarrhea Cause Check

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

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