How to Describe Your Symptoms
Use these phrases when speaking with a pharmacist. Showing the Japanese text is often clearer than attempting to pronounce it:
Translation devices and general-purpose translation apps have variable accuracy with medical and pharmaceutical terms. Prepared Japanese text is significantly more reliable.
When to See a Doctor
Most traveler's gastrointestinal complaints are self-limiting and resolve with OTC treatment and rest. However, certain symptoms require medical evaluation.
See a doctor if you have:
- Blood in stool (red or black/tarry) — indicates bleeding and requires urgent evaluation
- Severe abdominal pain that is constant, getting worse, or concentrated in one area
- Vomiting that won't stop (more than 24 hours), especially if you cannot keep fluids down
- High fever (38.5°C / 101.3°F) accompanying gastrointestinal symptoms — suggests bacterial infection
- Symptoms lasting more than 5–7 days without improvement
- Significant weight loss or extreme fatigue alongside digestive symptoms
- Yellow skin or eyes (jaundice — possible liver involvement)
- Severe right lower abdominal pain (possible appendicitis — emergency)
In Japan, gastrointestinal and internal medicine clinics (*naika*, 内科) handle most digestive complaints. Endoscopy is commonly available on short notice at larger clinics.
Find an internal medicine clinic near you using our medical facility search. Many major-city clinics have English-speaking staff or multilingual support available.
FAQ
Q: What is Seirogan and why does it smell so strong?
A: Seirogan (正露丸) is Japan's most famous anti-diarrheal medicine, containing wood creosote (*mokusō kreosoto*) as its active ingredient. The creosote has strong antiseptic properties effective against intestinal bacteria. The smell — described as tar-like or smoky — is from the creosote itself. It is jarring at first encounter but completely normal. The product is genuinely effective for diarrhea associated with minor gastrointestinal infections.
Q: Is Ohta Isan available in English-speaking countries?
A: Ohta Isan is sold in Japanese grocery stores and specialty shops in some countries with large Japanese communities (US, Australia), but is not mainstream in Western pharmacies. It is unique to Japan as an OTC product — buy it here if you want to try it.
Q: Can I take constipation medicine if I've only been constipated for 2 days?
A: Most gastroenterologists suggest waiting 3–4 days before using stimulant laxatives, as short-term constipation is very common during travel and often resolves spontaneously. In the meantime: stay well hydrated, eat fiber-rich foods (fruits, vegetables, rice), walk more, and drink warm water or coffee in the morning. If no result after 4–5 days, stimulant laxatives (Dulcolex, senna products) are appropriate.
Q: Are there stomach medicine options safe for pregnancy?
A: Magnesium hydroxide laxatives and certain antacids (calcium carbonate, magnesium carbonate) are generally considered lower risk in pregnancy, but all medication use during pregnancy should be cleared with a healthcare provider. Simethicone (Gascon) for gas is also generally considered safe. Stimulant laxatives (bisacodyl, senna) should be avoided in pregnancy. Always tell the pharmacist you are pregnant.
Q: What is OS-1 and is it better than regular sports drinks?
A: OS-1 is a medical-grade oral rehydration solution formulated to the WHO oral rehydration solution standard. It has the correct balance of sodium, potassium, and glucose to support efficient intestinal absorption — the same formulation used in clinical dehydration treatment. Regular sports drinks like Pocari Sweat are isotonic but not optimized for rehydration in the same way. For vomiting, diarrhea, or significant dehydration, OS-1 is the better choice. It is widely available at 7-Eleven, FamilyMart, and Lawson.
Q: I have food poisoning symptoms — should I take anti-diarrheal medicine?
A: For mild food-related diarrhea without fever and without blood in the stool, loperamide (Stoppa) is generally safe and effective. However, if you have fever or visible blood in the stool, anti-diarrheal medicine can prolong bacterial infection by preventing the body from expelling the pathogen — see a doctor instead. For a comprehensive guide, see our article on food poisoning in Japan.
Q: Does Japan have probiotics in pharmacy products?
A: Yes. Japan has a strong probiotic culture. Bifermin (ビオフェルミン) is the most popular OTC probiotic, available at virtually all drugstores in tablet and granule form. It is gentle enough for children and is commonly taken after antibiotics or for loose stool and diarrhea without infection. Japanese grocery stores also stock a wide range of probiotic fermented drinks (yakult, Kefir drinks, etc.).