Difficult defecation is a common symptom involving with patients'life quality. The stool pattern of these patients might be related to the contribution of gut microbiota. This pilot study proposed hypothesis that stool pattern could be used as a simple index to screen the potential candidates of fecal microbiota transplantation in patients with difficult defecation.

Difficult defecation is a common symptom involving with patients'life quality. The stool pattern of these patients might be related to the contribution of gut microbiota. This pilot study proposed hypothesis that stool pattern could be used as a simple index to screen the potential candidates of fecal microbiota transplantation in patients with difficult defecation. Patients underwent single FMT in this study were divided into hard-stool group and loose-stool group. All patients were assessed before FMT and during 12-week follow-up after FMT.

Inclusion Criteria:

1. age between 14-80 years old;
2. difficult defecation with more than six months (a. straining during defecation; b. sensation of incomplete evacuation; c. sensation of anorectal blockage; d. manual maneuvers to facilitate defecation).

Exclusion Criteria:

1. difficult defecation due to secondary factors (e.g. drugs, pelvic surgery, psychiatric disorders);
2. with history of gastrointestinal diseases such as cancer, inflammatory bowel diseases (IBD);
3. pregnant or breast-feeding women;
4. infection with pathogenic bacteria. Enrolled patients were divided into hard-stool group and loose-stool group according to their stool patterns. All patients were followed up for 12 weeks.