Life, often encountered to “diarrhea” as the main symptom of the patient, most patients are general inflammatory bowel disease, dyspepsia, dysentery and so on. But a small number of patients, diarrhea for a long time, but may be due to malignant tumors. This requires us to be vigilant! It is worth noting that most of the patients with tumor-induced diarrhea are mistaken for general gastrointestinal diseases, and are so paralyzed that they lose valuable treatment opportunities. Patients think that “diarrhea” is caused by general intestinal diseases or cold, unhygienic food, etc., so they often buy their own medicines and treat it at home. Some doctors who lack clinical experience often prescribe medicines according to diseases such as “enteritis”, resulting in repeated delays and delayed treatment. Therefore, we must pay attention to find out the cause of the disease, and never just anti-inflammatory diarrhea. As a matter of fact, malignant tumors in the digestive system, especially in the gastrointestinal tract, such as stomach cancer, colon cancer and rectal cancer, are very prone to diarrhea. However, this kind of cancer is easy to attract people’s attention, and the misdiagnosis rate is generally not high. What confuses people most is that diarrhea caused by tumors in other parts of the body is not easy to arouse people’s attention. Today, we will briefly sort out several kinds of tumors that may be related to long-term diarrhea. 1.Colorectal cancer: Constipation and diarrhea are very common in daily life, and these two symptoms may be the signals of intestinal cancer. Colorectal cancer includes colon cancer and rectal cancer, and its occurrence is mostly related to chronic inflammation of colon, colorectal adenoma, high-fat and low-fiber dietary habits, heredity and genes, etc. Early symptoms of colorectal cancer are usually not obvious, and with the development of the cancer, the patients will gradually develop symptoms such as abdominal pain, bleeding from stools, intestinal obstruction, and abdominal mass. Changes in defecation habits and stool traits are important indicators for early detection of rectal and colorectal cancer. Due to the stimulation of intestinal tract by tumor and its secretion, it will make people who originally have regular bowel movements suddenly become frequent or obviously reduce the number of bowel movements, alternating between constipation and diarrhea, morning diarrhea, etc., especially when accompanied by mucus blood stool, pus blood stool, blood in stool in bright red or jam color. Or when there are unexplained anemia, emaciation and weakness, one should be highly alert. When symptoms of colorectal cancer appear, patients must seek medical treatment in time. Initial stage of bowel cancer will also have the symptom of blood in stool, which is especially easy to be confused with hemorrhoids, resulting in many patients being diagnosed at advanced stage. Colorectal cancer can be easily misdiagnosed as hemorrhoids in its early stages, with more than 70% of colorectal cancer patients being misdiagnosed as hemorrhoids. The main reason for the high misdiagnosis rate is that there are many similarities between the clinical manifestations of anal and intestinal tumors and hemorrhoids, such as blood in stool and increased frequency of bowel movement. In addition, rectal cancer may compress the rectal veins and obstruct blood return, thus secondary to hemorrhoids, so the lesions are more easily concealed by the appearance of hemorrhoids. In fact, these can be avoided, no matter how similar the symptoms are, as long as the anoscopy is done and the pathology should be done, most of the anorectal tumors can be detected early. In addition, there are still subtle differences in careful observation. For example, if the bleeding is caused by hemorrhoids, then the blood and feces are separate; if it is caused by tumor, usually the blood and feces are mixed together. Some patients will also find that there is mucus mixed with feces, just like thick phlegm, which is a dangerous signal, it may be enteritis, or the cancer may break down and become infected. Gastric cancer: Gastric cancer ranks first among all kinds of malignant tumors in China, mostly related to Helicobacter pylori infection, heredity and genes, dietary habits, etc. Early stage of gastric cancer usually does not have obvious symptoms, and it is very similar to general gastroenteritis with diarrhea accompanied by nausea and acid reflux, so it is easy to be ignored by people. If you suddenly have unexplained diarrhea, black stools, accompanied by loss of appetite, weakness and fatigue, as well as nausea, burning sensation in stomach, vague pain or distension in epigastrium, etc., you should consider the possibility of tumor. Especially middle-aged people on the age of 40 and those who usually suffer from chronic peptic ulcer should pay attention to it and do gastroscopy and other investigations in time. Since stomach cancer occurs in the higher part of the abdomen, it usually presents with diarrhea symptoms. Diarrhea caused by stomach cancer is different from general diarrhea, which is usually accompanied by distension and pain in the upper abdomen without constipation, at this time, patients should go to hospital for gastroscopy in time. Liver cancer: Liver cancer is usually accompanied by cirrhosis, which can easily lead to portal hypertension or embolism, causing edema of the intestinal wall, accelerated intestinal peristalsis, digestive and secretion disorders, and thus diarrhea. Research shows that about half of the primary liver cancers have diarrhea symptoms 3 months before diagnosis, and the number of diarrhea each time ranges from 2-20 times. Therefore, if cirrhosis patients have diarrhea symptoms of unknown cause, they must remember to consult doctor in time. Among liver cancer patients, diarrhea as the first symptom is not uncommon. Some people have found that diarrhea is the first symptom for 5.8% of 3254 cases of liver cancer patients. The reason of diarrhea is that liver cancer cells can produce gastrin, vasoactive peptide, prostaglandin F2 and other substances in the process of division and proliferation, and after mast cells are stimulated by these substances, they will proliferate and release too much histamine, which will promote the increase of permeability of intestinal mucosal blood vessel wall and the increase of intestinal fluid secretion and cause diarrhea. Therefore, patients with daily diarrhea should not be treated as chronic enteritis or malabsorption syndrome. You should go to the hospital quickly to do serum alpha-fetoprotein (AFP), ultrasound, CT and other necessary tests, as well as early diagnosis. For middle-aged and old people, especially patients with chronic hepatitis or cirrhosis, if there is discomfort in the upper right side of the abdomen, enlargement of the liver area, boring pain and gradual aggravation, or loss of appetite, gradual loss of weight, it is necessary to go to the hospital as soon as possible to receive ultrasound, liver function, AFP and other tests to find out the cause of the disease. 4, islet cell tumor: islet cell tumor is a tumor occurring in islet cells, which is often seen in people between 20 to 50 years old. Islet cell tumor often causes diarrhea due to peptic ulcer disease, and patients usually have diarrhea after excessive fat and cholesterol intake, and at the same time, they also have nausea, fatigue, and loss of weight and other symptoms. Because the pancreas is often obscured by the stomach and transverse colon, it is not easy to detect pancreatic lesions on ordinary examinations, and the rate of early diagnosis of pancreatic cancer is low. Some patients with chronic pancreatitis and pancreatic cancer have chronic diarrhea due to pancreatic dysfunction. Therefore, if you experience unexplained epigastric discomfort, along with symptoms such as recurrent diarrhea, steatorrhea, dyspepsia, low back pain, jaundice not caused by gallstones, etc., and unexplained weight loss, it is important to pay attention to the problem and seek medical attention in time for checkups. Especially the high-risk groups with long-term smoking history, chronic pancreatitis, family history of pancreatic cancer, etc. Lung cancer and other cancers: research proves that some lung cancer cells can produce various regulatory peptides, such as adrenaline, parathyroid hormone, calcitonin, antidiuretic hormone and 5-hydroxytryptamine, etc. These hormones directly enter into the blood circulation, which will make people have carcinoid syndrome, and diarrhea is one of the prominent symptoms. In addition, there are also malignant tumors such as medullary thyroid tumor, growth inhibiting hormone tumor, gastrinoma and so on will also have diarrhea and indigestion symptoms. Diarrhea and diarrhea are very common, but if accompanied by the above symptoms, do not take it lightly, pull out the hidden risk factors of the disease in the body, timely diagnosis of the cause of the disease, and strive for early treatment of the disease.