The side effects of fecal colony transplantation include general side effects such as abdominal discomfort, endoscopy-related serious side effects and potential side effects. 1. General side effects: abdominal discomfort, bloating, flatulence, constipation, diarrhea, nausea, vomiting and fever. 2. Serious side effects: complications of endoscopy such as perforation and bleeding, adverse reactions related to sedative inhalation; transmission of intestinal pathogens; peritonitis, pneumonia, inflammatory bowel disease, fever, infection, post-infectious irritable bowel syndrome in peritoneal dialysis patients. 3. Potential side effects: transmission of unrecognized infectious agents that cause disease after a few years, e.g., hepatitis C, HIV; induction of chronic diseases based on alterations in gut microbiota, e.g., obesity, diabetes mellitus, atherosclerosis, colon cancer, non-alcoholic fatty liver disease, asthma, and autism. Fecal transplants carry some risks and it is advisable to seek medical attention if you are unwell.