Unexpected stomach troubles in Japan? Whether it’s food poisoning, overeating, or a sudden case of traveler’s diarrhea, it’s always helpful to know which over-the-counter options to reach for as the best diarrhea medicine in Japan.
Luckily, Japanese drugstores offer a variety of effective, easy-to-use anti-diarrheal medicines that can help you feel better fast.
Look out for labels like 下痢止め (geri-dome – anti-diarrheal) or 整腸薬 (seicho-yaku – intestinal medicine) when browsing the aisles.
Below is a list of the best diarrhea medicines at drugstores in Japan, recommended by drugstore staff for providing efficient and fast-acting relief. Don’t let sudden belly issues ruin your day!
Stopper Diarrhea Stopper EX (ストッパ下痢止めEX)
Best for: Fast-acting on the go
What Pharmacists Say:
If you suddenly get hit with diarrhea and stomach cramps, these grapefruit-flavored tablets are a convenient go-to and one of the best diarrhea medicines in Japan. They dissolve in your mouth without water—perfect for when you’re out or don’t have access to a drink. The key ingredient, Scopolia extract, helps relax your gut and slow things down, especially helpful if you’re dealing with painful or crampy diarrhea. They also contain berberine tannate, which soothes the stomach lining, reduces inflammation, and helps fight off bacteria that can cause diarrhea. Pharmacists recommend this option for fast relief when diarrhea is caused by indigestion, mild food poisoning, or eating something that didn’t agree with you.
Active Ingredient: Scopolia Extract Triple Powder (60 mg per tablet)
Dosage: Take the following amount by chewing or dissolving in your mouth. Not suitable for under-15-year-olds.
AgeDoseNumber of Times to Take Per DayDosage Interval15 years or over1 tabletLimit to 3 times a dayWait 4 hours before taking another dose
Price: Varies by pharmacy. Approximately ¥1,100 for 12 tablets.
Pishat Diarrhea Prevention OD Tablets (ピシャット 下痢止めOD錠)
Best for: On the go
Summary and What Pharmacists Say:
Pishat Diarrhea OD Tablets are great to have on hand because they dissolve in your mouth – no water needed. Super handy if you suddenly get hit with diarrhea while you’re out, like on the train or at work. They contain loperamide, which helps slow down the movement of your gut, so you’re not running to the bathroom constantly. It works fast, even for more serious cases, and pharmacists often recommend it for diarrhea caused by things like overeating, drinking too much, or catching a cold. Plus, the little pack is easy to throw in your bag and take with you anywhere.
Active Ingredient: Loperamide Hydrochloride (1mg per two tablets)
Dosage: Take the following amount by dissolving in your mouth, or taking it with water or hot water. Not suitable for under-15-year-olds
AgeDoseNumber of Times to Take Per DayDosage Interval15 years or over1 tabletTwice a DayWait 4 hours before taking another dose
Price: Varies by pharmacy. Approximately ¥1,100 for 12 tablets
Biofermin Antidiarrheal (ビオフェルミン下痢止め)
Best for: Natural choice with low side effects
What Pharmacists Say:
If your stomach’s upset but you don’t want to completely stop your system, Biofermin Antidiarrheal is a gentle option that supports your gut rather than just blocking things up. These easy-to-swallow tablets combine bifidobacteria, herbal extracts, and anti-inflammatory ingredients to help alleviate diarrhea and stomach pain, particularly associated with indigestion, food poisoning, or drinking contaminated water. Unlike stronger medications, this one allows your digestive system recover naturally, with fewer side effects, such as constipation. Pharmacists recommend it for people with sensitive stomachs or those dealing with ongoing digestive issues. It’s mild enough for longer-term use and a great choice when you need relief without harsh effects.
Active Ingredient: Berberine Tannate (300mg per nine tablets)
Dosage: Take the following amount with water or lukewarm water after a meal. Not suitable for under-11-year-olds
AgeDoseNumber of Times to Take Per DayDosage Interval15 years or over3 tabletsLimit to 3 times a dayWait 4 hours before taking another dose11-14 years2 tabletsLimit to 3 times a dayWait 4 hours before taking another dose
Price: Varies by pharmacy. Approximately ¥1,100 for 30 tablets
Anti-diarrheal tablets Kunihiro (下痢止め錠 クニヒロ)
Best for: Emergencies
What Pharmacists Say:
Kunihiro Diarrhea Tablets are a quick and convenient fix for sudden, painful diarrhea, especially when you’re out and about. These tablets melt in your mouth without water, making them perfect to keep handy for emergencies while commuting, traveling, or at work. The key ingredient, Scolytem extract, helps relax your intestines and ease stomach cramps, while berberine tannate fights bacteria and protects your gut. Pharmacists recommend this diarrhea medicine in Japan if you have sharp, sudden diarrhea caused by indigestion or issues related to food and water. Just remember, it’s not for everyday use and isn’t recommended for pregnant or breastfeeding women, or elderly people.
Active Ingredient: Berberine Tannate (300mg per three tablets)
Dosage: Take the following dose by chewing or allowing it to dissolve on your tongue. Not suitable for under-15-year-olds
AgeDoseNumber of Times to Take Per DayDosage Interval15 years or over1 tabletUp to three times a dayWait 4 hours before taking another dose
Price: Varies by pharmacy. Approximately ¥1,400 for 24 tablets
This information on the best diarrhea medicine in Japan is based on interviews with Japanese drugstore employees. It uses available product data as of July 2025. Always read the product packaging and instructions carefully, and consult a healthcare professional if you have any concerns or questions about your treatment.
For more information, read our full guide to drugstores in Japan.
This page has been brought to you as a public service of The Bluff Medical and Dental Clinic in Yokohama.
