Electrical Vagal Nerve Stimulation in Ulcerative Colitis

Inclusion Criteria: * Males or females between 18 and 76 years of age (inclusive). * Has a clinical diagnosis of UC at least 3 months before screening according to accepted international guidelines. * Quiescent disease. Disease activity will be assessed using the validated partial Mayo score and faecal calprotectin of \<4 and \<250 μg/g (18) respectively, scored within 3 months of entry into the study. Faecal calprotectin \<250 μg/g within 2 weeks before study entry to confirm that there has been no change in activity status. * Stable medications regimen for 3 months prior to entry into the study, defined as no additions to UC treatment or dosage escalations. * Patient is willing and able to participate in the study for the required duration, can understand and is willing to sign the ICF and agrees to undergo all protocol-related tests and procedures. * Patient has a BMI between 18 and 35 kg/m2 inclusive. Exclusion Criteria: * Has severe extensive colitis and is at imminent risk of colectomy. * Presence of a stoma or history of a fistula. * Currently taking any topical or oral corticosteroids. * Currently taking any anti-TNF therapy, azathioprine, 5-mercaptopurine or methotrexate. * Is pregnant, lactating or thinking of becoming pregnant during the study period, or of childbearing years and is unwilling to use and accepted form of birth control. (Female patients of child-bearing potential must have a negative urine pregnancy test at Screening/pre-dose on Day 1 of the study, excluding female patients of non-child bearing potential who are surgically sterile or post-menopausal. \[To be considered post-menopausal female patients must be without menses for 12 consecutive months before screening\].) * Patient has unstable acute illness or exacerbation or an unstable chronic illness or chronic disease (other than UC) that may affect assessments for this study as determined by previous physical examination, medical history, vital signs, ECG, and laboratory (serum biochemistry, haematology, urinalysis) assessments. (Note: Non-fasting elevations of cholesterol and triglycerides are not considered clinically significant.) * Patient with medical history of hepatitis B, hepatitis C or human immunodeficiency virus (HIV) infection * Has known or suspected severe cardiac disease (e.g., symptomatic coronary artery disease, prior myocardial infarction, congestive heart failure (CHF); * Has known or suspected cerebrovascular disease (e.g. prior stroke or transient ischemic attack, symptomatic carotid artery disease, prior carotid endarterectomy or other vascular neck surgery); * Has a clinically significant abnormal screening Electrocardiogram (ECG) e.g. second and third degree heart block, prolonged QT interval, atrial fibrillation, atrial flutter, history of ventricular tachycardia or ventricular fibrillation, or clinically significant premature ventricular contraction); * Has had a cervical vagotomy; * Has uncontrolled high blood pressure (systolic \>160, diastolic \>100 after 3 repeated measurements within 24 hours); * Is currently implanted with an electrical and/or neurostimulator device (e.g.. cardiac pacemaker or defibrillator, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, cochlear implant, sphenopalatine ganglion stimulator or occipital nerve stimulator); * Has been implanted with metal cervical spine hardware or has a metallic implant near the gammaCore® stimulation site; * Has a history of syncope (within last two years); * Has a history of seizures (within last five years); * Has a known history or suspected history of substance abuse or addiction (within last five years); * Has previously used the gammaCore® device.