Using 16S rRNA Gene Sequencing Analysis Intestinal Microbiota in Constipation Patients

1. Chronic constipation according to Rome III criteria, defined as two or fewer spontaneous, complete bowel movements (SCBMs) per week for a minimum of 6 months;
2. Age > 18 years;
3. BMI: 18.5-25 kg/m2;
4. Slow colonic transit confirmed by colonic transit test (colonic transit time (CTT) > 48 hours);
5. Normal anorectal manometry, with no evidence of dyssynergia and confirmed ability to expel rectal balloon;
6. No radiographic evidence of functional (i.e. pelvic floor dyssynergia) or anatomical (i.e. significant rectocele and intussusception) impediment to the expulsion of the radio-opaque contrast;
7. Disease duration > 1 year;
8. Traditional treatment with dietary modification, laxatives (including osmotic and stimulant laxatives), and biofeedback tried over the past 6 months without success;

Exclusion Criteria:

1. Bowel constipation due to innate factor (i.e. megacolon) or secondary interventions (i.e. drugs, endocrine, metabolic, neurologic or psychologic disorders);
2. History or evidence of gastrointestinal diseases (i.e. obstruction, cancer, inflammatory bowel diseases) ;
3. Previous abdominal surgery, except cholecystectomy, appendicectomy, tubal ligation and cesarean section;
4. Previous proctological or perianal surgery;
5. A constipation condition meeting the Rome III criteria for IBS or functional abdominal pain syndrome;
6. Pregnant or breast-feeding women;
7. Infection with enteric pathogen;
8. Usage of probiotics, prebiotics and/or synbiotics within the last month;
9. Usage of antibiotics and/or PPIs within the last 3 months;
10. Smoking or alcohol addiction within the last 3 months;