How Long Is Too Long for Diarrhea?
Medically reviewed by our MD Laboratory Director (a role required by CLIA; the director's name is on file in the CMS CLIA database, #45D2048957, and can be verified independently) · Editorial policy
Past four weeks, "wait and see" is not a plan. The differential has changed.CLIA #45D2048957 · CAP #8722734 · Same-day results · Walk-ins welcome
Acute diarrhea is under two weeks. Persistent is two to four weeks; chronic is beyond four. Once you cross those lines, the likely causes shift away from a passing infection toward parasites, malabsorption, inflammatory bowel disease, exocrine pancreatic insufficiency, celiac disease, microscopic colitis and IBS — and each one requires a different test.
Not sure what you need? Text us and we will set it up.
📱 Text (713) 832-8892 📞 Call (713) 266-0808
📱 Text (713) 832-8892 📞 Call (713) 266-0808
3707 Westcenter Dr Suite 100, Houston, TX 77042 · Walk-ins welcome
Where to look
| Suspicion | Test |
|---|---|
| Parasite | Molecular GI panel — Giardia and friends |
| Inflammation (IBD) | Fecal calprotectin / lactoferrin |
| Malabsorption / EPI | Fecal elastase |
| Celiac disease | Serology — while still eating gluten |
| SIBO / IBS | What can and cannot be established |
Go to an emergency department, not a lab, if you have: bloody diarrhea with fever, severe abdominal pain, signs of dehydration, a rigid abdomen, or you are an infant, elderly, pregnant or immunocompromised and deteriorating.
Chronic diarrhea with weight loss, blood, nocturnal symptoms or anemia is not IBS until everything else has been excluded. Those are alarm features and they need a gastroenterologist.
We name drugs, never doses. Treatment statements follow ACG, AGA, IDSA and CDC guidance; dose and duration are a physician's decision.
Same day, start to finish. Sample by 1:00 PM → results at 4:30 PM → if treatment is clinically appropriate, a licensed physician in our partner network sees you between 4:30 and 6:00 PM, a few minutes away. That window is reserved for patients tested here, and your slot is held the moment we take your sample — the slot is held, not hunted. On your own, a same-day appointment is nearly impossible; at an urgent care, you wait in the queue. STAT: ~2 hours, sample in by 3:00 PM.
FAQ
- Is this IBS?
- Possibly — but IBS is a diagnosis made after alarm features are excluded, not a label applied because tests were not run.
- Where do I start?
- A molecular pathogen panel plus inflammation markers is a reasonable first pass. The physician directs from there.
- Do I need a colonoscopy?
- Sometimes. Alarm features make it more likely. That is a gastroenterologist's decision.
- Can you do all of this same day?
- The pathogen panel, yes. Other markers follow their own workflows, and we will be honest about turnaround.
Not sure what you need? Text us and we will set it up.
📱 Text (713) 832-8892 📞 Call (713) 266-0808
📱 Text (713) 832-8892 📞 Call (713) 266-0808
3707 Westcenter Dr Suite 100, Houston, TX 77042 · Walk-ins welcome