Terminal constipation affects 13 to 20% of the french population. Anismus is defined by an absence of relaxation or a paradoxical contraction of the striated anal sphincter muscle during defecation.

Anismus is one of the main causes of terminal constipation. Anismus diagnosis is retained if 2 out of 3 examinations (manometry, electromyogram, defecography) are positive.

EndoFLIP® is a new medical device developed to measure distensibility of a hollow organ. Anal EndoFLIP® l could be a more sensitive and specific tool for detecting anismus in patients with distal constipation.

60 patients suffering from distal constipation will be included in order to perform, in addition to the usual examinations, an anal EndoFlip in order to test the sensitivity and specificity of this method for the diagnosis of anismus.

Inclusion Criteria:

• patient older than 18 years
• patient with distal constipation defined according to the Rome IV criteria, for at least 3 months and verified by a transit time study showing a predominant slowing of markers at the recto-sigmoid level.
• patient who read and signed the informed consent form

Exclusion Criteria:

• Patients with a predominant right of left colonic constipation;
• Pregnant woman or woman with no effective contraception and of childbearing age
• Patient with inflammatory bowel disease, ischemic colitis, history of colon or rectal cancer, infectious colitis or proctologic disease.
• Patient with anorectal malformation
• Patient with an history of pelvic floor radiotherapy
• Patient with a digestive stoma
• Insertion of the probe impossible or painful
• Patient who has participated to a clinical trial within 30 days prior to the inclusion visit
• Patient not understanding or reading French
• Patients under guardianship, curatorship, safeguard of justice
• Patient without liberty by administrative or judicial decision