Perianal Crohn's disease is a disabling disease associated with increased morbidity and impaired quality of life. It is associated with pain, discharge, fecal incontinence and sexual and psychological impairment. In refractory cases, a stoma may be necessary. A higher prevalence is seen with increasing Crohn's disease duration and appears to vary according to the disease location. The presence of symptoms associated with anorectal dysfunction, such as fecal incontinence, can sometimes poorly correlate with the presence of anal sphincter abnormalities. Moreover, even in patients without symptoms, the presence of anal sphincter abnormalities may have important implications for the future selection of type of delivery, and might even pose a contra-indication for certain types of anorectal surgeries.

Studies evaluating possible chronic complications of perianal Crohn's disease on anorectal function are lacking. There is a need for a better understanding of the chronic complications of this disease, and the role of high-resolution anorectal manometry in diagnosing these abnormalities during follow-up of these patients. This study will evaluate the chronic repercussions of perianal Crohn's disease in patients with a previous anal fistula and/or abscess that has healed and/or is inactive.

Inclusion Criteria:

1. ≥ 18 and ≤ 75 year-old patients
2. CD in clinical remission, defined by a Harvey-Bradshaw index <5
3. Perianal CD history, defined by the presence of a perianal fistula and/or abscess that were treated/heal/inactive
4. Perianal Disease Activity Index (PDAI) of ≤4
5. Asymptomatic or symptomatic patients (anorectal symptoms) will be included, as long they fulfill the other inclusion criteria, like for anorectal symptomatic patients having a PDAI≤4
6. Endoanal ultrasound without an image compatible with new/non-treated abscess or perianal fistula
7. Both previous simple or complex perianal fistula (according to the American College of Gastroenterology) will be considered.

Exclusion Criteria:

1. Women with previous vaginal delivery
2. Ileostomy
3. Previous anorectal surgery as hemorrhoidectomy or lateral sphincterotomy
4. Active rectal disease. No rectal involvement will be defined by no previous rectal involvement ever described or if previous involvement, endoscopy within 18 months showing no current involvement
5. Previous or current anal fissure
6. Anal stricture
7. Current or previous rectovaginal fistula (previous/last pelvic MRI).

A previous seton placement, abscess drainage, fistulotomy and lay open fistula are not an exclusion criteria. Patients with a current seton can only be included if the seton was place more than 24 weeks ago, and the endoanal ultrasound does not show any new/non-treated perianal fistula/abscess.

Patients attending hospital with diagnosed perianal Crohn's disease.