Efficacy and Safety of Fecal Microbiota Transplantation for Slow Transit Constipation

Inclusion Criteria: * 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; * Age ≥ 18 years; * BMI: 18.5-25 kg/m2; * Slow colonic transit confirmed by colonic transit test (colonic transit time (CTT) \> 48 hours); * Normal anorectal manometry, with no evidence of dyssynergia and confirmed ability to expel rectal balloon; * 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; * Disease duration \> 1 year; * Traditional treatment with dietary modification, laxatives (including osmotic and stimulant laxatives), and biofeedback tried over the past 6 months without success; Exclusion Criteria: * Bowel constipation due to innate factor (i.e. megacolon) or secondary interventions (i.e. drugs, endocrine, metabolic, neurologic or psychologic disorders); * History or evidence of gastrointestinal diseases (i.e. obstruction, cancer, inflammatory bowel diseases) ; * Previous abdominal surgery, except cholecystectomy, appendicectomy, tubal ligation and cesarean section; * Previous proctological or perianal surgery; * A constipation condition meeting the Rome III criteria for IBS or functional abdominal pain syndrome; * Pregnant or breast-feeding women; * Infection with enteric pathogen; * Usage of probiotics, prebiotics and/or synbiotics within t…