Chloride24hstlsrate
A test that measures the amount of chloride in stool collected over 24 hours to help diagnose conditions affecting chloride balance in the body.
{"This test measures chloride lost in stool over 24 hours","It helps diagnose cystic fibrosis and certain digestive disorders","A special container is used to collect all stool during a 24-hour period","Abnormal results may indicate chloride malabsorption or genetic conditions","No special diet restrictions are typically required before the test"}
Key facts at a glance
- LOINC
- 9742-8
- Short code
- CL24ST
- Synonyms
- Chloride 24h Stl-sRate
- Category
- electrolyte
- Sample
- stool
- Container
- Clean, dry, wide-mouthed stool collection container with tight-fitting lid
- Units
- not specified
- Ref low
- 0
- Ref high
- 15
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Ion-selective electrode (ISE) or titrimetric method
- CPT
- 82436
- SNOMED
- 314895002
- Specimen volume
- Complete 24-hour stool collection (entire volume)
- Stability
- Refrigerated (2-8°C): up to 7 days; Frozen (-20°C): up to 30 days. Transport to laboratory promptly after collection completion.
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The 24-hour stool chloride test measures the amount of chloride, an important electrolyte, that leaves your body in stool over a 24-hour period. Chloride helps maintain fluid balance, aids in digestion, and supports proper muscle and nerve function. This test is particularly important for detecting conditions where chloride is abnormally lost through the intestines.
Why is it done?
This test is primarily used to help diagnose cystic fibrosis, a genetic condition that affects mucus production throughout the body. In cystic fibrosis, the pancreas and lungs produce thick, sticky mucus. The test can also help identify congenital chloridorrhea, a rare genetic disorder where the intestines cannot properly absorb chloride. Additionally, it may be used to evaluate chronic diarrhea or malabsorption syndromes.
How to prepare
Before the test, your healthcare provider will give you specific instructions. Generally, you should continue your normal diet unless told otherwise. You will receive a large, clean container for collecting all stool during the 24-hour period. It is important to keep the container refrigerated or in a cool place. Make sure to label the container with your name, the date, and the start and end times of collection.
How the test works
You will collect all stool in the provided container for exactly 24 hours. This means every bowel movement during that time period must be saved. After the collection period is complete, you will return the container to the laboratory. The lab will measure the total amount of chloride in the collected stool and calculate the excretion rate over the 24-hour period.
What to expect during collection
The collection process is straightforward but requires attention. Start by urinating before having a bowel movement to avoid mixing urine with stool. After each bowel movement, use the collection device provided to transfer the stool into the large container. Keep the container refrigerated or in a cool place. Record the time of each collection. After 24 hours, seal the container and deliver it to your lab as instructed.
Reference range
0-15 mmol/24 hnot specified
Complete 24-hour stool collection required; refrigerate specimen during collection; avoid laxatives, enemas, and recent barium studies
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings2
Frequently asked questions
Does the test hurt?
Can I take my regular medications during collection?
What if I miss a bowel movement during the 24-hour period?
How long does it take to get results?
Do I need to fast before this test?
Sources
- 1
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 10, 2026. · Read our editorial policy