Brain stimulation (tACS) for adults with stubborn constipation and somatic symptom disorder

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This randomized, double-blind, placebo-controlled trial enrolls adults with refractory functional constipation and comorbid somatic symptom disorder and randomizes them to 4 weeks of active transcranial alternating current stimulation (tACS) or sham stimulation. Treatment effects will be measured during the treatment period and follow-up, focusing on bowel activity and patient-reported symptom burden. Primary outcomes include changes in complete spontaneous bowel movements (CSBM) and overall bowel-movement frequency, with secondary outcomes capturing constipation severity and quality of life (for example, PAC-SYM). Safety and tolerability will be monitored throughout, and all participants must meet Rome IV criteria for functional constipation and DSM-5 criteria for somatic symptom disorder.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Diagnosis of Functional Constipation (FC): Subjects must meet the diagnostic criteria for functional constipation as defined by the Rome IV criteria.
2. Low Frequency of Complete Spontaneous Bowel Movements (CSBM): During the 2-week screening period, subjects must have ≤2 complete spontaneous bowel movements per week.
3. Poor Response to Previous Treatment: Subjects must have been dissatisfied with prior treatments for functional constipation and have undergone at least 3 months of therapy (including laxatives or other prokinetic agents).
4. Diagnosis of Somatic Symptom Disorder (SSD): Subjects must meet the DSM-5 diagnostic criteria for somatic symptom disorder (SSD). All subjects will undergo a semi-structured clinical interview based on DSM-5 criteria, conducted by professionals trained in SSD diagnosis.

   * Criterion A: Presence of one or more distressing somatic symptoms that significantly affect daily life.
   * Criterion B: At least one of the following must be met:

     1. Excessive and persistent thoughts about the severity of symptoms;
     2. Persistently high levels of anxiety about health or symptoms;
     3. Excessive time and energy devoted to health concerns or symptoms.
   * Criterion C: Symptoms must persist for at least 6 months.
5. Age Range: Subjects must be between 18 and 80 years old.
6. No Concurrent Clinical Trials: Subjects must not participate in any other clinical trials during the study period.
7. Informed Consent: Subjects must voluntarily agree to participate and sign an informed consent form.

Exclusion Criteria:

1. Presence of organic diseases (such as tuberculosis, polyps, Crohn's disease, tumors, congenital megacolon, etc.), endocrine disorders (e.g., hypothyroidism), metabolic diseases (diabetes, thyroid dysfunction), or neurological disorders (e.g., Parkinson's disease);
2. Long-term use of medications that may affect intestinal function or induce constipation, such as Parkinson's drugs (excluding conventional laxatives, antidiarrheals, or intestinal stimulants; during the trial, participants are only allowed to take prescribed emergency medications, with detailed records of usage required);
3. History of chronic pain or substance abuse, such as opioids;
4. Diagnosed mental disorders with psychotropic medication use for over 3 months prior to the visit, or history of psychotropic or hormonal medication use for over 3 months;
5. Individuals at risk of self-harm or suicide, as assessed by a psychiatrist, or those requiring psychosomatic intervention;
6. History of allergy to psychiatric medications (e.g., fluoxetine), or contraindications to fluoxetine such as liver/kidney impairment or prolonged Q-T interval on ECG;
7. Pregnant or breastfeeding women;
8. Patients with benign or malignant tumors or autoimmune diseases;
9. Chronic conditions requiring long-term medication that may affect quality of life or interfere with examinations/treatment, including cardiovascular diseases, coagulation disorders or regular anticoagulant use (warfarin/heparin), liver/kidney diseases, organ failure, cognitive impairment, aphasia, etc.

Where it's running

• Xi'an International Medical Center Hospital
  Xi'an, Shaanxi, China Recruiting
• Xijing Hospital
  Xi'an, Shaanxi, China Recruiting

Study contacts

• Study coordinator: Zhifeng Zhao, Dr.
• Email: zhaozhifeng@outlook.com
• Phone: +8613519171072

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Ecological Momentary Intervention with Music or Reappraisal for Somatic Symptoms in SSD

  We’re testing whether listening to music or using cognitive reappraisal in daily life can reduce how strongly somatic symptoms feel and how much they impair daily living for adults with Somatic Symptom Disorder.

  Recruiting University of Vienna · Vienna, State of Vienna · NCT07646509

• Fiber supplement plus counseling for constipation during pregnancy

  A daily fiber supplement (PHGG-based) with vitamin mix and nutrition counseling is being tested to see if it helps pregnant people with functional constipation.

  Recruiting Société des Produits Nestlé (SPN) · Osasco, São Paulo · NCT07588633

• Comparing manual and electroacupuncture for functional constipation

  This trial will try manual acupuncture and electroacupuncture to see which produces more complete spontaneous bowel movements in adults with functional constipation.

  Recruiting Tongji Hospital · Wuhan, Hubei and 1 other locations · NCT07506122

• Optimizing ear-based vagus nerve stimulation for hard-to-treat constipation

  This trial will test whether gentle electrical stimulation of the ear (taVNS) twice daily for 20 days helps adults with refractory constipation have more complete spontaneous bowel movements and reduces laxative use.

  Recruiting Xijing Hospital of Digestive Diseases · Xi'an · NCT07344402

• Sea buckthorn supplement to improve bowel function in primary functional constipation

  This study will test whether a sea buckthorn (Hippophae rhamnoides) supplement at two different doses helps adults with primary functional constipation have more frequent, softer bowel movements and less bloating.

  Recruiting Istituto Farmochimico Fitoterapico: Epo Srl · Naples · NCT07082673

• Probiotics for treating constipation in adults

  This study is testing if a probiotic called ABKefir can help adults with constipation feel better after 8 weeks of treatment.

  Recruiting Chung Shan Medical University · Taichung, South · NCT06969872

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.