A Pilot Study Examining Low Sulfur Diet as Treatment for Persistent Symptoms in Quiescent Crohn's Disease

Inclusion Criteria:

* Prior diagnosis of Crohn's disease based on endoscopic, radiographic, and/or histologic findings
* Quiescent Crohn's disease as defined by fecal calprotectin level less than 150 micrograms/gram (mcg/g) stool and/or absence of inflammation on colonoscopy within 30 and 90 days, respectively, of enrollment
* Persistent symptoms will be defined by abdominal pain and/or diarrhea T-scores greater than or equal to 55 by the National Institutes of Health (NIH) Patient-Reported outcomes measurement information system Gastrointestinal scale (PROMIS-GI)

Exclusion Criteria:

* Prior total colectomy
* Presence of an end ileostomy or colostomy in place
* Changes in immunosuppressive medications within the past 4 weeks
* Use of antibiotics or probiotics within the past 4 weeks
* Active or suspected stricture/stenosis of the GI tract
* Habitual vegetarian or vegan diet
* Active or suspected gastrointestinal stricture or stenosis
* Unable or unwilling to follow a low sulfur diet
* Patients who are underweight as defined by BMI \< 18.5 kg/m2 or have significant unintentional weight loss as defined by \>7.5% body weight in the past 3 months
* Currently pregnant, breastfeeding, and/or unwillingness/inability to use contraception start of the study until the last 13C-mannitol:lactulose test is complete. Sexually active male participants and/or their female partners of reproductive potential must agree to use effective contraception from the start of the study and until the last 13C-mannitol:lactulose test is complete. Women who are breastfeeding must stop breastfeeding during and for at least 12 hours after consuming the 13C-mannitol:lactulose test. Breastfeeding women must pump and dispose of the breastmilk during this time period
* Subjects must agree to not donate sperm or ova (eggs) or breast milk from the start of the study until the last 13C-mannitol:lactulose test is complete.