Effect of FODMAP Diet on Pain, Quality of Life, and Sexual Function in Women With Pelvic Endometriosis and Gastrointestinal Symptoms (FODMAPendo)

Effect of FODMAP Diet on Pain, Quality of Life, and Sexual Function in Women With Pelvic Endometriosis and Gastrointestinal Symptoms: a Randomized Controlled Trial

The main objective of the study is to assess whether a dietary regimen based on the principles of the FODMAP diet, compared with the current treatment programme which does not include specific dietary recommendations, can improve pain symptoms in patients with symptomatic endometriosis and intestinal symptoms (i.e. bloating, nausea, constipation, diarrhoea and vomiting) attributable to irritable bowel syndrome, compared with a control group

Study Overview

• Status: Recruiting
• Conditions: Endometriosis
• Intervention / Treatment: Behavioral: FODMAP diet

Detailed Description

Endometriosis is defined as the presence of endometrial glands and stroma outside the uterine cavity, mostly, though not exclusively, in the pelvis. It is a chronic, estrogen-dependent inflammatory condition in which ectopic foci grow and proliferate under the action of estradiol, which plays a pro-inflammatory and anti-apoptotic role.

Pelvic pain represents the most typical manifestation of endometriosis. In particular, dysmenorrhea is the most frequent symptom.

In addition to typical gynecological symptoms, gastrointestinal symptoms (i.e., bloating, nausea, constipation, diarrhea, and vomiting) affect up to 90 percent of patients with endometriosis It has been reported how a diet low in oligosaccharides, disaccharides, monosaccharides, and fermentable polyols (FODMAP diet) is superior to other dietary treatments for the treatment of symptoms associated with irritable bowel syndrome.

Short-chain polysaccharides (FODMAPs) are found in a variety of fruits, vegetables and grains. FODMAPs are poorly absorbed in the gut, and are readily fermented by bacteria.

Their osmotic actions and gas production cause distention of the intestinal lumen inducing pain and bloating in patients with visceral hypersensitivity, with secondary effects on intestinal motility.

Although hormonal therapies represent the therapeutic cornerstone of endometriosis, we hypothesize that the FODMAP diet may represent a complementary and adjuvant approach for the treatment of abdominal/pelvic algic symptoms (and particularly bowel-type symptoms), resulting in significant improvement in the quality of life of affected women.

The primary objective of the study is to evaluate whether a dietary regimen based on the principles of the FODMAP diet versus the current treatment program, which does not include specific dietary indications, can improve algic symptoms in patients with symptomatic endometriosis and the presence of bowel symptoms (i.e., bloating, nausea, constipation, diarrhea, and vomiting) referable to irritable bowel syndrome,

Eligible women will be selected among those attending the Endometriosis Clinic of the "L. Mangiagalli ", IRCCS Ca 'Granda Foundation and Ospedale Maggiore Policlinico, and will be randomized into two homogeneous groups ("intervention" and "control") (1:1): the intervention group will consist of women with symptomatic endometriosis and concomitant bowel symptoms under estro-progestin or progestin treatment, who will be asked to follow a dietary regimen based on the principles of the FODMAP diet; women in the control group will not be given specific instructions about the diet to follow.

Women will be randomized and assigned to two groups: 1) "FODMAP diet" (FD) group; 2) "usual diet" (UD) group. All patients participating in the study will undergo clinical and ultrasonographic evaluation at the beginning of the study, after 3 months and after 6 months. On these occasions, women will be routinely asked to complete some questionnaires, one on pain (a numerical rating scale, NRS), to the evaluation of gastrointestinal symptoms (NRS related to intestinal symptoms, such as abdominal bloating, nausea, constipation, diarrhea and vomiting), one on quality of life (the Short Form-12 questionnaire, SF-12), one on psychological status (the Hospital Anxiety and Depression scale, HADS), one on sexual functioning (theFemale Sexual Function Index, FSFI) and one on the global impression of change (Patients' Global Impression of Change scale, PGIC). Women will also be asked to rate the degree of satisfaction with their treatment.

Patients randomized into the intervention group will participate in an initial meeting with the dietitian during which they will receive targeted nutritional counseling. They will be provided with the dietary pattern to follow. Follow-up of the diet will include telephone follow-up 6 to 8 weeks after the start of the study, at 3 months and at 6 months to assess dietary adherence.

• Study Type: Interventional
• Enrollment (Estimated): 150
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Giussy Barbara; Phone Number: +393471753089; Email: giussy.barbara@policlinico.mi.it

Study Locations

• Italy
  • Milan, Italy, 20122
    • Recruiting
    • Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico
    • Contact: Dhouha Dridi, MD; Phone Number: +393429370961; Email: dhouha.dridi@policlinico.mi.it
    • Contact: Giussy Barbara, MD; Phone Number: +393471753089; Email: giussy.barbara@unimi.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age between 18 and 45 years
• BMI between 18.5 and 24.9,
• Surgical, clinical or instrumental diagnosis of endometriosis
• Presence of bowel symptoms (i.e., bloating, nausea, constipation, diarrhea, and vomiting) referable to irritable bowel syndrome, on estro-progestin or progestin treatment or in the absence of hormonal treatment

Exclusion Criteria:

• Associated conditions that may cause pelvic pain independent of the presence of endometriosis (e.g., pelvic varices and salpingitis outcomes)
• chronic inflammatory bowel disease (Crohn's disease or ulcerative rectocolitis).
• patients with obstructive uropathy, subocclusive intestinal stenosis
• complex adnexal masses or typical endometriomas greater than 5 cm in diameter.
• women who are obese (BMI ≥ 30) or underweight (BMI < 18)
• women on vegetarian-vegan dietary regimens,
• women with metabolic diseases that require specific dietary indications such as in the case of diabetes and celiac disease.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: FODMAP diet group; Patients randomized to the treatment arm were proposed to follow a FODMAP diet throughout the study period	Behavioral: FODMAP diet; Diet low in oligosaccharides, disaccharides, monosaccharides and fermentable polyols
No Intervention: Usual diet group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of pain related syntomps in patients with bowel symptoms	The primary objective of the study is to evaluate whether a dietary regimen based on the principles of the FODMAP diet versus the current treatment program, which does not include specific dietary indications, can change algic symptoms in patients with symptomatic endometriosis and the presence of bowel symptoms (i.e., bloating, nausea, constipation, diarrhea, and vomiting) referable to irritable bowel syndrome, compared with a control group. The outcome will be measured trough Numerical Rating Scale (NRS) on dismenorrea, dyspareunia, non menstrual pelvic pain and dyschezia.	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gastrointestinal syntomps, patient satisfaction, health-related quality of life, psychological conditions, patient's overall condition and anthropometric parameters	Assessment of patient satisfaction during treatment, measured using a five-point Likert scale; Assessment of gastrointestinal symptoms (abdominal bloating, nausea, constipation, diarrhea, and vomiting) using a numerical rating scale (NRS, 0 to 10); The impact on health-related quality of life assessed using the Short-Form Health Survey 12 (SF-12); The impact on sexual function using the Female Sexual Function Index (FSFI) questionnaire; The impact on patients' psychological conditions using the HADS (Hospital Anxiety and Depression Scale); The patient's overall condition using the Patients' Global Impression of Change (PGIC) scale, a seven-point scale (greatly improved, much improved, slightly improved, unchanged, slightly worsened, muc; Changes in anthropometric parameters through changes in BMI and impedance analysis of body composition	6 months

Collaborators and Investigators

• Sponsor: Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2024
• Primary Completion (Estimated): November 15, 2026
• Study Completion (Estimated): December 15, 2026

Study Registration Dates

• First Submitted: May 10, 2024
• First Submitted That Met QC Criteria: May 12, 2026
• First Posted (Actual): May 15, 2026

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 12, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Genital Diseases, Female; Endometriosis; Diet, Food, and Nutrition; Physiological Phenomena; Nutritional Physiological Phenomena; Diet; Elimination Diets; FODMAP Diet
• Other Study ID Numbers: 3655_S_P

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No