DRUG
Linaclotide
The observation group 1 was given Linaclotide in 1 day combined with 4L of Compound Polyethylene Glycol Electrolyte Powder to clear the intestine, and the observation group 2 was given Linaclotide in 1 day combined with 4L of Compound Polyethylene Glycol Electrolyte Powder to clear the intestine. observation group 3 was given Linaclotide in 3 day combined with 3L of Compound Polyethylene Glycol Electrolyte Powder to clear the intestine. Intestinal cleanliness and the incidence of adverse reactions of patients in each group were compared.