Antibiotic-induced enteritis

　　Long-term use of broad-spectrum antibiotics can lead to dysbiosis of the intestinal flora, causing the proliferation of antibiotic-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Proteus, certain Clostridium species, and Candida albicans, etc., leading to enteritis after. Excessive use of antibiotics changes the existing microbial flora in the intestines or leads to the appearance of antibiotic-resistant strains, causing enteritis.

　　Severe cases of antibiotic-induced enteritis can be fatal. Initially, the colon mucosa becomes congested and pinpoint bleeding appears, with small abscesses forming in the mucosal crypts. The abscesses gradually enlarge, causing the superficial layer of the local intestinal mucosa to necrose and slough off, forming superficial small ulcers that can involve the submucosa. The ulcers can fuse and expand or penetrate each other to form fistulas. As the lesion progresses further, large areas of necrotic intestinal mucosa can appear, forming large ulcers. The remaining intestinal mucosa becomes congested, edematous, and hyperplastic, forming a polypoid appearance, known as pseudopolyps. Pseudopolyps are slender, with no clear distinction between the pedicle and the body. Sometimes, ulcers can penetrate the intestinal wall, causing pericolonic abscesses and secondary peritonitis. The involved colon can become adherent to adjacent abdominal organs.

　　The phenomenon of excessive use of antibiotics is increasing, and excessive use of antibiotics not only does not have a good therapeutic effect on the disease but can also lead to enteritis induced by antibiotics.

　　1. Staphylococcus aureus enteritis

　　Primary Staphylococcus aureus enteritis is rare. It is caused by bacterial invasion of the intestinal wall and the production of enterotoxins. The main symptoms are diarrhea, with mild cases having several bowel movements a day and gradually recovering after stopping medication: severe cases have frequent diarrhea, with stools having a foul smell, yellow or dark green, watery, with a lot of mucus, and a few cases have bloody stools. It can lead to dehydration, electrolyte imbalance, and acidosis. It is accompanied by abdominal pain and varying degrees of toxic symptoms such as fever, nausea, vomiting, weakness, delirium, and even shock. Stool microscopy shows a large number of pus cells and clusters of Gram-positive cocci, culture shows growth of Staphylococcus aureus, and the coagulase test is positive.

　　2. Pseudomembranous enterocolitis

　　Pseudomembranous colitis is caused by Clostridium difficile. Almost all antibiotics can trigger the disease, except vancomycin and aminoglycoside antibiotics used topically in the gastrointestinal tract, and the disease can occur within 1 week of starting treatment or up to 4-6 weeks after discontinuing medication. It is also seen in weakened patients after surgical procedures, intestinal obstruction, intussusception, megacolon, and renal failure.

　　Pseudomembranous colitis primarily presents with diarrhea, with mild cases having several bowel movements a day, which quickly recover after discontinuing antibiotics. Severe cases have frequent diarrhea, with stools being yellow or yellow-green, watery, and may contain pseudomembranes, with a few cases having bloody stools. It can lead to dehydration, electrolyte imbalance, and acidosis. It is accompanied by abdominal pain, distension, and toxic symptoms, with severe cases potentially developing shock. Rectal and sigmoidoscopy can be performed on suspected cases. Anaerobic bacterial culture and tissue culture methods for detecting cytotoxins can assist in diagnosis.

　　3. Fungal enteritis

　　Fungal enteritis is often caused by Candida albicans and is often accompanied by thrush. The stool frequency increases, it is loose and yellowish, with more foam and mucus, and sometimes there are curd-like small pieces (colonies). Occasionally, there is blood in the stool. Microscopic examination shows fungal bud cells and pseudofilaments. Cultivate stool fungi for identification.

　　Since antibiotic-induced enteritis is caused by the misuse of antibiotics, changing the existing microbial flora in the intestines, or the appearance of antibiotic-resistant strains, it is necessary to use antibiotics rationally and prevent abuse to prevent this disease.

　　The examination results of antibiotic-induced enteritis vary due to different pathogenic bacteria causing the infection.

　　1. Staphylococcus aureus enteritis

　　Stool microscopy shows a large number of pus cells and clusters of Gram-positive cocci. Cultivation shows growth of Staphylococcus aureus, and the coagulase test is positive.

　　2. Pseudomembranous enterocolitis

　　Cultivate anaerobic bacteria in stool and detect cytotoxins by tissue culture method.

　　3. Fungal enteritis

　　Microscopic examination shows fungal bud cells and pseudofilaments. Cultivate stool fungi for identification.

　　Patients with antibiotic-induced enteritis can have light diet, consume semi-liquid foods that are easy to digest, and can also consume yogurt containing probiotics. In severe cases or those with severe nausea and vomiting, fasting is required, and parenteral nutrition is provided. Gradually return to normal diet after symptoms subside.

　　Patients with long-term use of antibiotics are particularly prone to antibiotic-induced enteritis. So, how should it be treated?

　　1. Correct electrolyte and acid-base balance disorders, provide nutritional support, and transfuse plasma and albumin if necessary.

　　2. Strict bedside isolation to prevent cross-infection in the hospital; if the condition permits, stop using the original antibiotic or switch to other narrow-spectrum antibiotics.

　　For those with obvious diarrhea and abdominal pain, symptomatic treatment with microecological preparations, astringents, antispasmodics, and other drugs can be given.