Megarectum in Adults

NCT07599527 | Not Yet Recruiting

• 2 other identifiers: 2026/0116/OB2026-A00636-45
• Study Type: observational
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

Severe functional constipation associated with a pathological increase in rectal volume, with or without colonic dilation, is known as megarectum. In the absence of an organic cause, megarectum is called idiopathic. This condition can begin at birth, in childhood, or in adulthood. The exact incidence of idiopathic megarectum (IM) is unknown, but it is considered a rare condition. Clinically, IM is usually considered in the context of chronic constipation that is refractory to traditional treatments and accompanied by rectal distension, abdominal pain, encopresis, and recurrent fecal impaction. The pathophysiological basis of IM remains poorly understood. A study using a rectal barostat-a device that measures rectal capacity and compliance (the rectum's ability to distend) by controlled distension of a rectal balloon-identified two distinct subgroups of patients with MI: (1) those with increased rectal compliance, who can be described as having "physiological" megarectum, in which marked rectal hyposensitivity-characterized by the absence of perception of rectal distension-and hypocontractility lead to chronic fecal accumulation and progressive overdistension due to loss of rectal elasticity; and (2) those with normal rectal compliance, who can be considered to have anatomical megarectum. It is not yet known whether these subgroups reflect different underlying etiologies. Furthermore, in patients with physiological megarectum, it is unclear whether the condition is primary or secondary to long-term rectal distension.

Conditions

Idiopathic Megarectum

Keywords

severe functional constipation; understanding pathophysiology.

Outcome Measures

Primary Outcomes (2)

• To determine if patients with Idiopathic MegaRectum (MI) have a history of earlier constipation in childhood than constipated patients without megarectum

  This involves comparing the history of constipation that may reveal anorectal dysfunction in childhood in constipated adults with MI and in constipated control subjects without megarectum through clinical questioning.

  1 day

• To determine if patients with Idiopathic MegaRectum (MI) have a history of more digestive symptoms in childhood than constipated patients without megarectum

  This involves comparing the history of digestive symptoms that may reveal anorectal dysfunction in childhood in constipated adults with MI and in constipated control subjects without megarectum through clinical questioning.

  1 day

Secondary Outcomes (23)

• Comparison of environmental factors in constipated adults with MI and in constipated control subjects without megarectum

  1 day

• Comparison of environmental factors in constipated adults with MI and in constipated control subjects without megarectum

  1 day

• megarectum phenotyping

  1 day

• megarectum phenotyping

  1 day

• megarectum phenotyping

  1 day

Interventions

Idiopathic megarectum group OTHER

questionnaires documented by patients with suspected megarectum on anorectal manometry and confirmed by rectal barostat

Constipated patient group OTHER

questionnaires completed by adult patients consulting for functional constipation without suspected megarectum on anorectal manometry

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

* Patients with idiopathic Mega-Rectum (MI) treated in the Digestive Physiology Department between 2016 and 2026 for the performance of a rectal barostat to confirm the megarectum suspected by anorectal manometry. * Constipated patients recruited consecutively during consultations by physicians in the Digestive Physiology department, and whose anorectal manometry, performed as part of routine care, ruled out the diagnosis of megarectum

You may qualify if:

• Idiopathic megarectum (IM) group:
• Adult patients presenting with chronic constipation according to the Rome criteria;
• Patients with megarectum suspected by anorectal manometry and confirmed by rectal barostat;
• Isolated, idiopathic megarectum (no known cause);
• Constipated group:
• Constipated adult patients presenting consecutively with chronic functional constipation according to the Rome criteria;
• Patients without megarectum suspected by anorectal manometry.

You may not qualify if:

• Patients who are not constipated;
• Hirschsprung's disease;
• Patients with anorectal malformation;
• Patients with known neurological conditions;
• Patients with endocrine disorders that may cause constipation;
• Patients taking constipating medications such as morphine or neuroleptics;
• Patients with a potential organic and/or drug-induced cause of constipation;
• Constipation secondary to medication;
• Patients unable to complete a questionnaire;
• Patients deprived of their liberty, under guardianship, or curatorship

Sponsors & Collaborators

• University Hospital, Rouen: lead

Study Sites (1)

Digestive Physiology Department

Rouen, 76031, France

Location

Study Officials

• Anne-Marie AL LEROI, Professor

  University Rouen Hospital

  STUDY DIRECTOR

Central Study Contacts

Nabila NL LAAJAIL, Director

CONTACT

02 32 88 82 65; Nabila.Laajail@chu-rouen.fr

vincent VF FERRANTI, ARC

CONTACT

02 32 88 82 65; Vincent.Ferranti@chu-rouen.fr

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Target Duration: 1 Day
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 13, 2026
• First Posted: May 20, 2026
• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 2, 2028
• Study Completion (Estimated): December 1, 2028
• Last Updated: May 20, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1)