1. Rotavirus enteritis: It usually occurs in autumn and winter, and is sporadic or small epidemic. The virus is transmitted through the fecal-oral route and respiratory tract. It is more common in infants and young children between 6 and 24 months old. The incubation period is 1 to 3 days and is often accompanied by fever and upper respiratory tract infection symptoms. The onset is sudden, with vomiting at the beginning of the disease, followed by diarrhea, and the stools are watery or egg soup-like, with a small amount of mucus and no fishy smell, several to more than 10 times a day. Dehydration and acidosis are often associated. This disease is a self-limiting disease, with a course of 3 to 8 days, sometimes longer, and a small number of white blood cells are occasionally found in stool microscopy. A large amount of virus is excreted in the stool within 1 to 3 days of the disease, and can last up to 6 days. Serum antibodies generally rise after 3 weeks, and the virus is difficult to isolate. Immunoelectron microscopy, ELISA or nucleic acid electrophoresis are all helpful for diagnosis.

2. Norwalk virus enteritis: more common in older children and adults, with clinical manifestations similar to rotavirus enteritis.

3. Escherichia coli enteritis: It often occurs from May to August, and the severity of the disease varies. The stool of pathogenic Escherichia coli enteritis is egg drop soup-like, smelly, contains more mucus, occasionally blood streaks or sticky peptone, is often accompanied by vomiting, and usually has no fever or systemic symptoms. Mainly manifested by water and electrolyte disorders. The course of the disease is 1 to 2 weeks. Toxigenic Escherichia coli enteritis has an acute onset. The main symptoms are vomiting, diarrhea, watery stools, and no white blood cells. Obvious water, electrolyte, and acid-base balance disorders often occur, and the course of the disease is 5 to 10 days. Invasive Escherichia coli enteritis has an acute onset, high fever, frequent diarrhea, sticky peptone-like stools with pus and blood, and is often accompanied by symptoms such as nausea, abdominal pain, tenesmus, and sometimes severe poisoning symptoms or even shock. Clinical symptoms are difficult to distinguish from bacillary dysentery, and stool culture is required for identification. In hemorrhagic Escherichia coli enteritis, the frequency of stools increases, and the stools start out as yellow watery stools, and then turn into bloody and watery stools with a special odor. Stool microscopy shows a large number of red blood cells, but often no white blood cells. With abdominal pain. May be accompanied by hemolytic uremic syndrome and thrombocytopenic purpura.

4. Campylobacter jejuni enteritis: It can occur throughout the year and is more common in summer. It can spread or occur in outbreaks. The incidence rate is highest among infants and young children aged 6 months to 2 years old. Livestock and poultry are the main sources of infection. It is transmitted from animals to humans or from humans to humans through the fecal-oral route. The incubation period is 2 to 11 days. The onset is acute and symptoms are similar to those of bacillary dysentery. Fever, vomiting, abdominal pain, diarrhea, mucus or pus and blood in the stool, with a foul smell. Infection with toxin-producing strains can cause watery stools. Stool microscopy shows a large number of white blood cells and varying numbers of red blood cells, which can be complicated by severe enterocolitis, sepsis, pneumonia, meningitis, endocarditis, pericarditis, etc.

5. Yersinia enterocolitis: It usually occurs in winter and spring, and is more common in infants and young children. The incubation period is about 10 days. There are no obvious prodromal symptoms. Clinical symptoms are age-related. Children under 5 years old have diarrhea as the main symptom, and their stools are watery, mucusy, pusy or bloody. Stool microscopy shows a large number of white blood cells, often accompanied by abdominal pain, fever, nausea and vomiting. The main symptoms are lower abdominal pain, increased white blood cells, and accelerated erythrocyte sedimentation rate, which is similar to acute appendicitis. This disease can be complicated by mesenteric lymphadenitis, erythema nodosum, reactive arthritis, sepsis, myocarditis, acute hepatitis, liver abscess, conjunctivitis, meningitis, urethritis or acute nephritis, etc. The course of disease is 1 to 3 weeks.

6. Staphylococcus aureus enteritis: rarely primary, mostly secondary to the application of large amounts of broad-spectrum antibiotics or secondary to chronic diseases. The onset is sudden and the symptoms of poisoning are severe. Symptoms include fever, vomiting, and frequent diarrhea. There are varying degrees of dehydration, electrolyte imbalance, and severe cases of shock. The stool is yellow-green at the beginning of the disease. After 3 to 4 days, it often turns into fishy, ??seawater-like stool with a lot of mucus. Stool microscopy showed a large number of pus cells and Gram-positive bacteria. Stool culture showed growth of Staphylococcus aureus and was positive for coagulase.

7. Pseudomembranous colitis: It is more common after long-term use of antibiotics. The long-term use of antibiotics leads to intestinal flora disorder, causing Clostridium difficile to multiply in large numbers and produce necrotic toxins. The main symptoms are diarrhea, yellow and watery stools or mucus, a few with blood, pseudomembrane discharge (intestinal tube shape), accompanied by fever, abdominal distension, and abdominal pain.

Abdominal pain often precedes or occurs simultaneously with diarrhea. It is often accompanied by significant hypoalbuminemia, water and electrolyte disorders, and systemic weakness and chronic consumption. In children with mild cases, diarrhea usually stops 5 to 8 days after stopping the drug. In severe cases, dehydration, shock and death may occur. If the child's diarrhea occurs after stopping the drug, or if antibiotics are continued after the diarrhea occurs, the course of the disease is often delayed.

8. Candida albicans enteritis: mostly occurs in frail, malnourished children and those who abuse broad-spectrum antibiotics or adrenocortical hormones for a long time. Thrush is often present in the mouth. The frequency of stool increases, the color is yellowish or green, there is more foam, and sometimes small pieces (colonies) like tofu can be seen in the mucus. Fungal spores and pseudohyphae can be seen in the stool under the microscope. Fecal fungal culture can help to identify it.