Taking a laxative after a colonoscopy does not usually cause a person to become dehydrated. The laxative that is usually used for a colonoscopy is compounded polyethylene glycol electrolyte dispersions. The main ingredients are sodium chloride, sodium bicarbonate, and polyethylene glycol. It needs to be melted with water and consumed. Common adverse reactions manifest as nausea, vomiting, and a feeling of fullness. Occasionally, hives, dermatitis, etc. are seen. Dehydration of the body is mainly due to the loss of water and electrolytes in the body. Compound Polyethylene Glycol Electrolyte Bulk itself is an electrolyte and needs to be taken with plenty of water. Although the symptoms of diarrhea will be produced after taking it. But because of the constant replenishment, the water and electrolytes in the body are balanced under normal circumstances. It should be noted that the use of the drug is prohibited if you suffer from intestinal obstruction, intestinal perforation, gastric retention, gastrointestinal bleeding, toxic enteritis, toxic megacolon, or intestinal torsion patients, or if you are allergic to any of the ingredients. It needs to be used after clarification of the purpose and after prescription by a medical professional.