Effects of Constipation Treatment in Chronic Kidney Disease: A Pilot Feasibility Trial

Inclusion Criteria:

1. Male or female patients >18 years old.

2. Patients able and willing to provide written informed consent and HIPAAauthorization.

3. CKD stages G3-G5 without kidney replacement therapy with estimated glomerularfiltration rate (eGFR) <60 mL/min/1.73m2 calculated using the Chronic KidneyDisease-Epidemiology Collaboration (CKD-EPI) 2021 creatinine equation.

4. Functional or opioid-induced constipation based on the Rome IV criteria.

5. Patients must refrain from taking any laxatives for at least one week prior toscreening, although rescue with one bisacodyl 5 mg tablet will be allowed when apatient does not have a bowel movement for ≥3 consecutive days or when symptomsbecome intolerable.

6. A negative pregnancy test in female patients prior to enrolment, unless the patientis two years postmenopausal or has had a documented tubal ligation or hysterectomy.

Exclusion Criteria:

1. History of drug abuse, anorexia nervosa, or bulimia.

2. History of irritable bowel syndrome, inflammatory bowel disease, or Clostridiumdifficile bacterial infection (ever).

3. Liver cirrhosis or chronic active hepatitis (patients with treated hepatitis can beincluded).

4. Galactosemia.

5. Allergies to lactulose.

6. History of gastrointestinal surgery except appendectomy.

7. Use of antibiotics or immunosuppressants within 30 days prior to the enrollment inthe study.

8. Use of pre- or probiotics within 30 days prior to enrollment in the study.

9. Women who are pregnant, capable of becoming pregnant and not participating in anacceptable form of birth control, or who are breast feeding.

10. Patients currently participating in another interventional study.

11. Major surgery within one month prior to enrollment in the study or planned surgerywhile the patient is in the study, other than dialysis vascular access surgery.

12. Patients who the investigator determine have a medical status that would precludethe patient's participation.

13. Patients on hemodialysis or peritoneal dialysis.

14. Patients with a functional kidney transplant.

15. Patients with past lactulose use.