Reduce Crohn's-Associated Diarrhea With Sodium Channel Therapy

Inclusion Criteria:

- Meet diagnostic criteria for Crohn's Disease with active diarrhea Either with active disease or in remission (as defined by endoscopic or radiographic findings) but experiencing symptoms (e.g., diarrhea, abdominal pain)

- Have greater than three loose stools per day

Exclusion Criteria:

- Male and female subjects <18 years of age

- Significant change in medication including prednisone, antidepressant medications, or stimulants within the last 4 weeks

a. Allowances include: Rectal hydrocortisone, rectal mesalamine, addition of prednisone (up to 20mg) for flares, etc.

- Regular (daily) use of opioids or other drugs of abuse including heavy alcohol or marijuana use

- Severe psychiatric disease including schizophrenia, psychosis, suicidal depression

- Previous use of ranolazine within 2 months prior to enrollment

- Prior use of ranolazine which was discontinued for safety or tolerability

- Metabolic derangement defined as liver function tests >3x upper limit of normal or severe renal disease defined as calculated creatinine clearance <30 mL/min

- Have liver cirrhosis

- Concurrent use of CYP3A inhibitors, inducers, or substrates

a. These may include: ketoconazole, itraconazole, clarithromycin, nefazodone, nelfinavir, ritonavir, indinavir, and saquinavir, diltiazem, verapamil, erythromycin, fluconazole, grapefruit juice or grapefruit-containing products, rifampin, rifabutin, rifapentine, phenobarbital, phenytoin, carbamazepine, and St. John's Wort.

- Concurrent use of statin medications, Digoxine, TCA antidepressants or anti-psychotics, or metformin

- Concurrent use of OCT2 substrates

- Concurrent use of drugs transported by P-gp or drugs metabolized by CYP2D6

- Concurrent use of drugs known to prolong the QT interval

- A family history of (or congenital) long QT syndrome or known acquired QT interval prolongation

- Inability or refusal to give informed consent for any reason including a diagnosis of dementia or cognitive impairment

- Patients who are pregnant or breastfeeding

- Patients who are enrolled in other investigational drug studies or who have taken investigational drugs within 30 days before enrollment

- Other factors which in the opinion of the investigator could potentially impact the study outcomes (e.g., underlying disease, medications, history) or prevent the participant from completing the protocol (poor compliance or unpredictable schedule)