The Effects of Bethanechol on Glucose Homeostasis

Inclusion Criteria: * Ages 18-65. No minors will be studied. * Individuals must be able to consent for their own participation (no mental impairment affecting cognition or willingness to follow study instructions). * Healthy volunteers with no clinical evidence of T2DM (see below). * Otherwise healthy volunteers that have impaired glucose tolerance (see below). * Otherwise healthy volunteers with Diet Controlled T2DM (see below). * Otherwise healthy volunteers with T2DM that take oral agents only and if the subject's pre-existing oral anti-diabetic agents can be safely discontinued for 48 hours prior to Oral Glucose Tolerance Test. * Otherwise healthy volunteers with T2DM who do not use insulin for blood glucose control. * Persons with HbA1c ≤ 9%. * Women of childbearing potential must be currently taking/using a method of birth control that is acceptable to the investigators. A pregnancy test will be done at the beginning of each visit. Any woman with a positive pregnancy test will be removed from the study. Exclusion Criteria: * \<18years of age or \>65 years of age * Lacks cognitive ability to sign the consent \&/or follow the study directions for themselves * Women unwilling to comply with using an acceptable method of contraception during the course of the study, or who are currently breast-feeding. * Any subject whose screening HbA1c is \>9.0% * Type 2 diabetes requiring the use of supplemental insulin @ home * Volunteers with a history of Acute Pancreatitis * Volunteer with a history of Chronic Pancreatitis and/or risk factors for chronic pancreatitis including hypertriglyceridemia (triglycerides \>400mg/ml) hypercalcemia (blood calcium level \>11.md/dl) and/or the presence of gallstones. * Volunteers with a history of gastrointestinal disorders, particularly related to gastric motility/emptying such as gastric bypass, documented gastro-paresis in diabetic volunteers. * Volunteers with a history of cancer. Exception: skin cancer. * Diabetics that have the potential to have a low blood sugar without them being aware that their blood sugar is low (hypoglycemia unawareness). * Known heart, kidney. liver or pancreatic disease requiring medications. * Unwillingness to allow blood glucose level adjustment (if needed) with IV insulin. * Subjects with hyperthyroidism, coronary artery disease, peptic ulcer, asthma, chronic bronchitis, or COPD.