What is the treatment for a patient with worms in their stool, presenting with gastrointestinal symptoms such as abdominal pain, diarrhea, or weight loss?

Treatment of Worms in Stool

The treatment depends entirely on identifying which worm species is present, as different parasites require different medications and some carry serious risks if treated incorrectly. 1, 2

Immediate Identification Strategy

If you can see the worm, its appearance determines your next steps:

• Earthworm-sized (15-35 cm), pink or white, cylindrical worm = Ascaris lumbricoides (roundworm) 2
• Flat, ribbon-like segments (proglottids) = Tapeworm species 2
• Tiny white thread-like worms = Pinworm (Enterobius vermicularis) 1

Critical action: Submit the worm specimen for laboratory identification immediately, as visual identification alone is unreliable. 2

Diagnostic Testing Required

Before treating, you must:

• Collect 3 consecutive stool samples for concentrated microscopy with ova and parasite (O&P) examination, as a single visible worm does not exclude concurrent parasitic infections 2, 3
• Order complete blood count with differential to assess for eosinophilia, which suggests tissue-migrating helminths 2, 3
• For pinworm specifically, use the cellophane tape test applied to perianal area in the morning (not stool examination), with three tests on consecutive mornings achieving 90% sensitivity 4

Treatment by Confirmed Species

Ascaris (Roundworm)

Single-dose treatment with any of the following: 1

• Albendazole 400 mg PO, OR
• Mebendazole 500 mg PO, OR
• Ivermectin 200 μg/kg PO

No routine follow-up needed unless symptoms persist. 2

Tapeworms - CRITICAL DISTINCTION REQUIRED

For Taenia solium (pork tapeworm):

• Use niclosamide 2 g PO as single dose ONLY 1, 2
• NEVER use praziquantel unless neurocysticercosis has been excluded first - this is potentially fatal as killing intestinal worms may worsen CNS disease 1, 2, 3
• Mandatory follow-up: serology and potential imaging to exclude cysticercosis, plus public health reporting 2

For Taenia saginata (beef tapeworm):

• Praziquantel 10 mg/kg PO as single dose 1, 2
• Clinical follow-up at 3 months to ensure no recurrence 2

If Taenia species uncertain: Use niclosamide 2 g PO single dose 1

Pinworm (Enterobius vermicularis)

Single-dose treatment (repeat in 2 weeks): 1, 5

• Albendazole 400 mg PO, OR
• Mebendazole 100 mg PO

Treat all household members simultaneously, especially with multiple or repeated symptomatic infections 5

Hookworm (Ancylostoma/Necator)

Albendazole 400 mg PO daily for 3 days 1

In severe disease with significant anemia: Add prednisolone 40-60 mg PO once daily; seek specialist advice as intensive care may be needed 1

Whipworm (Trichuris trichiura)

Combination therapy is essential due to low cure rates with monotherapy: 1

• Mebendazole 100 mg PO twice daily PLUS
• Ivermectin 200 μg/kg PO once daily
• Duration: 3 days for both medications

Hymenolepis (Dwarf Tapeworm)

Praziquantel 25 mg/kg PO as single dose 1

Alternative: Niclosamide 2 g PO once daily for 7 days 1

Common Pitfalls to Avoid

Do not assume a single worm means a single infection - multiple parasite species can coexist, making stool microscopy mandatory even when a worm is visible 2

Do not treat T. solium with praziquantel without excluding neurocysticercosis first - this is the most dangerous error in parasitic treatment 1, 2, 3

Do not rely on single negative stool test - sensitivity is limited; always collect at least 3 samples over consecutive days 3

Do not use routine stool O&P for pinworm diagnosis - the cellophane tape test is required 4, 3

Prevention Measures for Reinfection

For all intestinal worms: 6

• Wash hands and fingernails with soap frequently, especially before eating and after using toilet
• Wash all fruits and vegetables thoroughly or cook well
• Wear shoes in endemic areas
• Use proper sanitation facilities

For pinworm specifically (highly contagious): 6, 5

• Wear tight underpants day and night, change daily
• Vacuum or damp mop bedroom floors for several days after treatment
• Wash bed linens and night clothes after treatment (don't shake them)
• Keep toilet seats clean
• Clip fingernails short, avoid nail-biting and scratching perianal area

Special Considerations

Pregnant women: Pyrantel pamoate is preferred over mebendazole and albendazole 5

Immunocompromised patients: Require broader parasitic workup and may need prolonged treatment courses 3

Public health reporting: Tapeworm cases, particularly T. solium, must be reported to local health authorities with household contact screening 3