{"id":333,"date":"2026-01-27T13:28:48","date_gmt":"2026-01-27T04:28:48","guid":{"rendered":"https:\/\/clinicten.jp\/zh-cn\/?page_id=333"},"modified":"2026-01-27T13:28:49","modified_gmt":"2026-01-27T04:28:49","slug":"diarrhea","status":"publish","type":"page","link":"https:\/\/clinicten.jp\/zh-cn\/internal-medicine\/internal-symptoms\/diarrhea\/","title":{"rendered":"Diarrhea and Bloody Stool"},"content":{"rendered":"
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Content Supervision<\/p>

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KOMAI TSUBASA<\/p>\n

KOMAI TSUBASA<\/p> <\/div>\n <\/div>\n

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KOMAI TSUBASA<\/p>\n

KOMAI TSUBASA<\/p> <\/div>\n

Physician \/ Board-Certified Internist (Japanese Society of Internal Medicine) \/ Board-Certified Interventional Cardiologist (Japanese Association of Cardiovascular Intervention and Therapeutics) \/ ECG Certification Level 1<\/p>

I have worked diligently as a young physician on the front lines of cardiovascular emergency medicine. While I feel an “immense sense of fulfillment” when patients brought in by ambulance successfully return to their normal lives, I have also witnessed many cases of “the ultimate consequences of lifestyle diseases” that could not be saved.\r\nI aspire to be a family doctor whom patients can consult as casually as they would a friend, with the goal of helping people before it’s too late. I am also involved in medical education to improve health literacy among the Japanese public.<\/p> <\/div>\n\t<\/div>\n<\/div>\n<\/div>\n\n\n

What Are Diarrhea and Bloody Stool?<\/h2>\n\n\n\n

Stool that contains a large amount of water and becomes liquid is called \u201cdiarrheal stool,\u201d while stool that is softer than normal is referred to as \u201cloose stool.\u201d When diarrheal or loose stools occur repeatedly and are accompanied by abdominal discomfort or pain, this condition is called \u201cdiarrhea\u201d or \u201cdiarrheal illness.\u201d<\/p>\n\n\n\n

Bloody stool, in a broad sense, refers to stool that contains blood. More precisely, it refers to stool that appears bright red or reddish-brown. This indicates bleeding from a location closer to the anus, such as the rectum or colon, where the blood has not yet changed color and remains visibly red when mixed with the stool.\n
In contrast, bleeding from areas closer to the mouth, such as the esophagus or stomach, results in stool that appears black. This is because when bleeding occurs farther from the anus, the blood takes longer to pass through the digestive tract and is altered in color by gastric acid and digestive enzymes before being excreted.<\/p>\n\n\n\n

What to Keep in Mind When Experiencing Diarrhea or Bloody Stool<\/h2>\n\n\n\n

When you have diarrhea, the intestines are abnormally active. For this reason, it is important to allow the intestines to rest. Warming the abdomen and lying down to rest as much as possible can be helpful. Meals should consist of easily digestible foods. Because diarrhea causes fluid loss, be sure to maintain adequate hydration. If diarrhea is the only symptom, you may try using over-the-counter antidiarrheal medication. However, if symptoms do not improve after taking such medication, you should visit a medical facility.<\/p>\n\n\n\n

In the case of bloody stool, bleeding is occurring somewhere in the body, and leaving it untreated can be dangerous. In general, you should seek medical care without relying on self-judgment. The appearance of bloody stool, including its color, is very important for diagnosis. When visiting a doctor, it can be extremely helpful to take a photo of the stool and show it to the physician as a reference for diagnosis.<\/p>\n\n\n\n

Medical Conditions That May Cause Diarrhea or Bloody Stool<\/h2>\n\n\n\n
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Diarrhea can occur even without a specific illness and may be caused by overeating, excessive alcohol consumption, stress, or exposure to cold. Common disease-related causes include infectious gastroenteritis caused by viruses such as norovirus and food poisoning. In these cases, vomiting is often present as well. The likelihood of infectious gastroenteritis is higher if high-risk foods such as oysters were consumed before symptoms appeared or if there are others around with similar symptoms.<\/p>\n<\/div>\n\n\n\n

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\n\t\t\t<\/i>\t\t\tInfectious gastroenteritis
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Hemorrhoids are the most common cause of bloody stool. Other possible causes include colorectal diseases such as ulcerative colitis and Crohn\u2019s disease. For example, in ulcerative colitis, the stool is often mixed with mucus and blood, and in more severe cases, abdominal pain and fever may also be present.<\/p>\n<\/div>\n\n\n\n

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\n\t\t\t<\/i>\t\t\tUlcerative colitis
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Urgent Conditions Associated With Diarrhea or Bloody Stool<\/h2>\n\n\n\n

O157, which has been widely discussed as a cause of food poisoning, is a type of enterohemorrhagic Escherichia coli. As the name suggests, infection can cause bleeding in the intestines, leading to bloody stool. While most adults recover from O157 infection, children are at higher risk of developing severe illness and therefore require careful attention.<\/p>\n\n\n\n

Bloody stool can also occur in cases of colorectal cancer. Colorectal cancer is a condition for which a cure can be aimed for if it is detected and treated at an early stage. If individuals aged 40 or older notice bloody stool, it is strongly recommended that they seek medical evaluation as early as possible.<\/p>\n\n\n\n

summary<\/h2>\n\n\n\n