Idiopathic MegarectumMEGA-ORIGINENCT07599527
Megarectum in Adults
An observational study of Idiopathic Megarectum, run by University Hospital, Rouen at 1 site in France.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Idiopathic Megarectum
- What is being tested?
- Idiopathic megarectum group and Constipated patient group
- How many people
- 120 participants
- Where
- 1 siteFrance
- Study dates
- 1 Jun 2026to 1 Dec 2028
- How long will I take part?
- 1 Day
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
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
Who may be able to join
- 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.
Who cannot join
- 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;
Show all 10Show fewer
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Megarectum in Adults: Congenital or Acquired Pathology?
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.
Read the detailed description
The aim of this study is to identify and characterize elements of the clinical history, particularly early ones, associated with the disease, in order to contribute to the understanding of its pathophysiology.
To this end, the project aims to analyze the personal and family histories of patients with idiopathic bowel dysfunction (BD) and compare them with a population of constipated patients without BD, in order to determine the chronology of the onset of the condition (from birth, childhood/adolescence, or later) and to evaluate the risk factors for BD. It is also planned to describe the population of patients with BD to confirm whether or not different subgroups exist.
A better understanding of the pathophysiology of BD should make it possible to prevent the condition (if secondary to dyssynergia present in childhood) and/or to provide earlier, more appropriate management, thus avoiding acute episodes of bowel obstruction.
- Conditions
- Idiopathic Megarectum
- Being tested
- Idiopathic megarectum group, Constipated patient group
- Keywords
- severe functional constipation, understanding pathophysiology.
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Idiopathic megarectum groupOther
questionnaires documented by patients with suspected megarectum on anorectal manometry and confirmed by rectal barostat
Constipated patient groupOther
questionnaires completed by adult patients consulting for functional constipation without suspected megarectum on anorectal manometry
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 1 day
Secondary outcomes (23)
Comparison of environmental factors in constipated adults with MI and in constipated control subjects without megarectum
Determination of the presence of environmental factors in childhood: breastfeeding, repeated early antibiotic therapy, drug treatment in childhood and indication (antibiotics, anticholinergic treatments, opiates, morphine, etc.) through clinical questioning
Measured: 1 day
Comparison of environmental factors in constipated adults with MI and in constipated control subjects without megarectum
Presence of psychosocial factors in childhood: psychosocial or school-related stress, anxiety and depressive disorders as revealed by clinical questioning
Measured: 1 day
megarectum phenotyping
The aim is to phenotype the megarectum using anorectal manometry to distinguish an "acquired" profile from a "congenital" profile. The measured indicators will be anal tone, amplitude and duration of voluntary contraction, the presence of the rectoanal inhibitory reflex; the amplitude of the rectoanal inhibitory reflex at 30 ml of rectal distension; the presence of rectosphincter dyssynergia; the amplitude of rectal contraction during straining; the percentage of anal relaxation during straining; the residual pressure during straining; the threshold volume for perceiving rectal distension; the constant perceiving volume; the maximum tolerable volume; and rectal compliance.
Measured: 1 day
megarectum phenotyping
The aim is to phenotype the megarectum using Balloon evacuation test is to assess a patient's ability to evacuate stools, particularly in cases of constipation or suspected defecation disorder. This test is based on the concept of success or failure.
Success:
The patient manages to expel the balloon within a timeframe considered normal (often < 1 to 2 minutes, according to protocols).
This suggests that the recto-anal evacuation mechanism is generally functioning correctly.
Failure:
The patient is unable to expel the balloon or takes an abnormally long time.
This may indicate a defecation disorder, for example:
anorectal dyssynergia (poor muscle coordination), rectal hypocontractility, or a functional obstruction to evacuation.
Measured: 1 day
megarectum phenotyping
The aim is to phenotype the megarectum using rectal Barostat is to allow the measurement of rectal distension volumes to obtain the desired rectal pressure
Measured: 1 day
megarectum phenotyping
The aim is to phenotype the megarectum using rectal Barostat is to allow the measurement of rectal distension volumes to obtain the rectal compliance
Measured: 1 day
megarectum phenotyping
The aim is to phenotype the megarectum using rectal Barostat is to allow the measurement of rectal distension volumes to obtain the maximum tolerable volume;
Measured: 1 day
megarectum phenotyping
The aim is to phenotype the megarectum using imagery is to assess rectal size in diameter
Measured: 1 day
megarectum phenotyping
The aim is to phenotype the megarectum using imagery is to assess colon size in diameter
Measured: 1 day
Constipation Severity Score Evaluation
This assessment is carried out using the Kess scores. The KESS score (KESS score = Knowles-Eccersley-Scott Symptom score) is intended to assess the severity of chronic constipation. It takes into account:
frequency of bowel movements; difficulty passing stool; feeling of incomplete evacuation; use of laxatives; pain or straining; duration of the problem.
The higher the score, the more severe the constipation.
Measured: 1 day
Constipation Severity Score Evaluation
This assessment is carried out using the Francis scores. The Francis score (or IBS-SSS: Irritable Bowel Syndrome Severity Scoring System) is used to measure the severity of Irritable Bowel Syndrome.
It assesses:
intensity of abdominal pain; frequency of pain; bloating/distension; bowel movement irregularities; and impact on quality of life.
The total score ranges from 0 to 500:
< 75: no or very mild symptoms; 75-175: mild; 175-300: moderate; 300: severe.
Measured: 1 day
fecal incontinence severity score
The Cleveland Clinic score will be used to assess the severity of chronic constipation. This score assesses several factors:
frequency of bowel movements; difficulty of defecation; straining; feeling of incomplete evacuation; abdominal pain; time spent on the toilet; need for assistance (laxatives, enemas, digital defecation); duration of constipation.
Each item is assigned a number of points.
In practice:
< 8: mild constipation; 8-15: moderate constipation; > 5: severe constipation
Measured: 1 day
Quality of life score assessment
The quality of life score will be assessed using the GIQLI questionnaires. The GIQLI (Gastrointestinal Quality of Life Index) is a questionnaire used to measure quality of life related to digestive diseases. The questionnaire comprises 36 questions. Each question is scored from 0 to 4 on the following scale:
0 = very poor condition / significant symptoms 4 = no problems The maximum score is 144. A high score indicates good digestive health. A low score indicates significant impact of digestive disease.
Measured: 1 day
Quality of life score assessment
The quality of life score will be assessed using the PAC-QOL questionnaire. The PAC-QOL (Patient Assessment of Constipation - Quality Of Life) is a specific questionnaire used to assess the impact of chronic constipation on quality of life.The questionnaire typically contains 28 questions divided into several areas: 1) physical discomfort; 2) psychosocial discomfort; 3) worries/concerns; 4) satisfaction. Each item is rated on a scale of 0 to 4.
A low score indicates a good quality of life; A high score indicates a significant impact of constipation.
Measured: 1 day
Quality of life score assessment
The quality of life score will be assessed using the FIQL questionnaires. The FIQL (Fecal Incontinence Quality of Life Scale) is a questionnaire designed to assess the impact of fecal incontinence on quality of life. The FIQL measures the psychological, social, and emotional impact of fecal incontinence, going beyond simply the frequency of leakage.
It explores, in particular: social discomfort; anxiety; self-image; limitations in daily activities; emotional impact.
The FIQL comprises 29 questions divided into 4 domains:
- Lifestyle; 2) Behavior; 3) Depression/Self-Perception; 4) Embarrassment. Each question is scored on a scale of 0 to 4. A high FIQL indicates a better quality of life. A low FIQL indicates a significant impact of incontinence.
Measured: 1 day
Predictive factors for each of these profiles in terms of medical history
Identify predictive factors for each of these profiles in terms of family history during the clinical interview with the patient (severe constipation leading to surgery (and type of surgery) or difficult to treat medically, onset of constipation in childhood or adulthood, Hirschsprung's disease, colonic inertia, chronic intestinal pseudo-obstruction, gastroparesis, stoma, gastrostomy, enteral or parenteral nutrition, anorectal malformation, neurological malformation)
Measured: 1 day
Predictive factors for each of these profiles in terms of medical history
Identify the predictive factors of each of these profiles in terms of personal history during the clinical interview with the patient (severe constipation requiring surgical intervention (and type of intervention) or difficult to treat medically, onset of constipation in childhood or adulthood, Hirschsprung's disease, colonic inertia, chronic intestinal pseudo-obstruction, gastroparesis, stoma, gastrostomy, enteral or parenteral nutrition, anorectal malformation, neurological malformation).
Measured: 1 day
Current symptoms
Identify current symptoms: encopresis, fecal incontinence, dyschezia, abdominal bloating, abdominal pain, number of bowel movements per week, stool consistency according to the Bristol Stool Scale
Measured: 1 day
Predictive factors for each of these profiles in terms of medical history
information search regarding the age of toilet training in childhood during the clinical interview with the patient.
Measured: 1 day
Predictive factors for each of these profiles in terms of medical history
information search regarding childhood digestive symptoms during the clinical interview with the patient.
Measured: 1 day
Predictive factors for each of these profiles in terms of medical history
information regarding stool frequency in childhood and stool consistency in childhood during the clinical interview with the patient.
Measured: 1 day
Predictive factors for each of these profiles in terms of medical history
research for information regarding the factors identified as triggers of constipation during the clinical interview with the patient.
Measured: 1 day
Predictive factors for each of these profiles in terms of medical history
information search regarding possible pain during defecation during the clinical interview with the patient.
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 May 2026
- Study start1 Jun 2026 (estimated)
- Primary completion2 Jun 2028 (estimated)
- Study completion1 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Idiopathic MegarectumStudies of the same condition, open and under way.
- More trials run by University Hospital, RouenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 120 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- University Hospital, Rouen
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Anne-Marie AL LEROI, Professor, Study director, University Rouen Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07599527
- Sponsor's protocol ID
- 2026/0116/OB
- Other IDs
- 2026-A00636-45
- Acronym
- MEGA-ORIGINE
- Status last verified
- May 2026
- First submitted
- 13 May 2026
- Last updated
- 20 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Megarectum in Adults: Congenital or Acquired Pathology?
- ClinicalTrials.gov ID
- NCT07599527
- Acronym / sponsor ID
- MEGA-ORIGINE / 2026/0116/OB
- Conditions
- Idiopathic Megarectum
- Keywords
- severe functional constipation, understanding pathophysiology.
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- University Hospital, RouenUniversity, hospital or other
- Study start
- 1 Jun 2026 (estimated)
- Primary completion
- 2 Jun 2028 (estimated)
- Study completion
- 1 Dec 2028 (estimated)
- First posted
- 20 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
The aim of this study is to identify and characterize elements of the clinical history, particularly early ones, associated with the disease, in order to contribute to the understanding of its pathophysiology.
To this end, the project aims to analyze the personal and family histories of patients with idiopathic bowel dysfunction (BD) and compare them with a population of constipated patients without BD, in order to determine the chronology of the onset of the condition (from birth, childhood/adolescence, or later) and to evaluate the risk factors for BD. It is also planned to describe the population of patients with BD to confirm whether or not different subgroups exist.
A better understanding of the pathophysiology of BD should make it possible to prevent the condition (if secondary to dyssynergia present in childhood) and/or to provide earlier, more appropriate management, thus avoiding acute episodes of bowel obstruction.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Target follow-up
- 1 Day
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- 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
Key inclusion criteria (7 listed)
- 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 adult patients presenting consecutively with chronic functional constipation according to the Rome criteria;
Key exclusion criteria (10 listed)
- 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;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Idiopathic megarectum groupquestionnaires documented by patients with suspected megarectum on anorectal manometry and confirmed by rectal barostat | Other | – |
| Constipated patient groupquestionnaires completed by adult patients consulting for functional constipation without suspected megarectum on anorectal manometry | Other | – |
Primary outcome
To determine if patients with Idiopathic MegaRectum (MI) have a history of earlier constipation in childhood than constipated patients without megarectum
Time frame: 1 day
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.
To determine if patients with Idiopathic MegaRectum (MI) have a history of more digestive symptoms in childhood than constipated patients without megarectum
Time frame: 1 day
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.
23 secondary outcomes
Comparison of environmental factors in constipated adults with MI and in constipated control subjects without megarectum
Time frame: 1 day
Comparison of environmental factors in constipated adults with MI and in constipated control subjects without megarectum
Time frame: 1 day
megarectum phenotyping
Time frame: 1 day
megarectum phenotyping
Time frame: 1 day
megarectum phenotyping
Time frame: 1 day
megarectum phenotyping
Time frame: 1 day
megarectum phenotyping
Time frame: 1 day
megarectum phenotyping
Time frame: 1 day
megarectum phenotyping
Time frame: 1 day
Constipation Severity Score Evaluation
Time frame: 1 day
Constipation Severity Score Evaluation
Time frame: 1 day
fecal incontinence severity score
Time frame: 1 day
Quality of life score assessment
Time frame: 1 day
Quality of life score assessment
Time frame: 1 day
Quality of life score assessment
Time frame: 1 day
Predictive factors for each of these profiles in terms of medical history
Time frame: 1 day
Predictive factors for each of these profiles in terms of medical history
Time frame: 1 day
Current symptoms
Time frame: 1 day
Predictive factors for each of these profiles in terms of medical history
Time frame: 1 day
Predictive factors for each of these profiles in terms of medical history
Time frame: 1 day
Predictive factors for each of these profiles in terms of medical history
Time frame: 1 day
Predictive factors for each of these profiles in terms of medical history
Time frame: 1 day
Predictive factors for each of these profiles in terms of medical history
Time frame: 1 day
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 May 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Anne-Marie AL LEROI, Professor study director
University Rouen Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Idiopathic Megarectum, run by University Hospital, Rouen at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 20 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Nabila NL LAAJAIL, Director (02 32 88 82 65 ext. +33, Nabila.Laajail@chu-rouen.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To determine if patients with Idiopathic MegaRectum (MI) have a history of earlier constipation in childhood than constipated patients without megarectum (time frame: 1 day). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 May 2026.