• Number of subjects recruited [ Time Frame: 2 years ]
  60 subjects
• Proportion of subjects who complete the study [ Time Frame: 12 week study ]
  At least 80% subjects will complete study
• Proportion of dosages of drug/placebo that are taken by participants [ Time Frame: 12 week study ]
  At least 80% of dosages will be taken by participants

• Number of subjects recruited [ Time Frame: 1 year ]
  60 subjects
• Proportion of subjects who complete the study [ Time Frame: 12 week study ]
  At least 80% subjects will complete study
• Proportion of dosages of drug/placebo that are taken by participants [ Time Frame: 12 week study ]
  At least 80% of dosages will be taken by participants

• Abdominal Pain Intensity: weekly average of worst daily (in past 24 hours) abdominal pain score scale of 0 (No pain) -10 (Worst imaginable pain) [ Time Frame: 12 week study ]
  An Abdominal Pain Intensity Weekly Responder is defined as a patient who experiences a decrease in the weekly average of worst abdominal pain in the past 24 hours score (measured daily) of at least 30% compared with baseline weekly average.
• Abdominal Bloating Intensity: weekly average of worst daily (in past 24 hours) abdominal bloating rating on a scale of 0 (absent) - 4 (very severe) [ Time Frame: 12 week study ]
  A Bloating Intensity Weekly Responder is defined as a patient who experiences a decrease in the weekly average of worst bloating pain in the past 24 hours score (measured daily) of at least 30% compared with baseline weekly average
• Bowel movement frequency: Number of Complete Spontaneous Bowel Movements (CSBMs) each week [ Time Frame: 12 week study ]
  A Stool Frequency Weekly Responder is defined as a patient who experiences an increase of at least one CSBM per week from baseline

• Drug: Botanical Tincture
  Study participants will meet with the Investigator at baseline and week 2, 6, and 10 after the study period begins. Trial continuation criteria at 2 weeks after the start of the study includes abdominal pain intensity and stool frequency. Participants randomized to Botanical Tincture will have a 2-week withdrawal period. On the visits study participants may expect to be asked about epidemiologic information, IBS medications, IBS Quality of Life survey instruments, and daily diary of pain scale, bloating scale, and number of bowel movements.
  Other Name: BT
• Other: Placebo
  Study participants will meet with the Investigator at baseline and week 2, 6, and 10 after the study period begins. Trial continuation criteria at 2 weeks after the start of the study includes abdominal pain intensity and stool frequency. On the visits study participants may expect to be asked about epidemiologic information, IBS medications, IBS Quality of Life survey instruments, and daily diary of pain scale, bloating scale, and number of bowel movements.

• Experimental: Botanical Tincture
  The 12-week study includes a 2-week screening, 8-week treatment, and 2-week withdrawal periods. A 2-week screening period will be used to establish the presence and persistence of trial entry criteria and train patients in the mode of data collection. Participants randomly assigned to the Botanical Tincture arm at Week 2 will take 2.5 ml by mouth once a day at any time during the day that they choose. Participants who received Botanical Tincture during the study will be followed by a 2-week randomized withdrawal design to address the need for maintenance treatment to prevent sign or symptom recurrence. The participant will be randomly reassigned to receive either Botanical Tincture or placebo at a dosage of 2.5 ml once a day by mouth at any time during the day that they prefer.
  Intervention: Drug: Botanical Tincture
• Placebo Comparator: Placebo
  Participants randomly assigned to placebo arm at Week 2 will take 2.5 ml by mouth once a day at any time during the day that they choose during the 8-week treatment period.
  Intervention: Other: Placebo

Inclusion Criteria:

• Patients meeting ROME IV criteria for the diagnosis of irritable bowel syndrome that requires that patients have had recurrent abdominal pain on average at least 1 day per week during the previous 3 months that is associated with 2 or more of the following :
• Related to defecation (may be increased or unchanged by defecation)
• Associated with a change in stool frequency
• Associated with a change in stool form or appearance
• Abdominal Pain Intensity: average of worst daily (in past 24 hours) abdominal pain score of >= 3 on a 0 to 10 point scale over last week
• Stool Frequency: < or = to 3 Complete Spontaneous Bowel Movement(CSBM) in the previous week
• Reported bloating rating > or = 2 on 5-point scale [0 (absent) - 4 (very severe)] in previous week
• English speakers, as all surveys are in English

Exclusion Criteria:

• Patients with known hypersensitivity to any component of the trial drugs
• History of eating disorders
• Patients with a history of diseases with abdominal symptoms that can resemble IBS
• Presence of any other known acute or chronic gastrointestinal disorder
• History of abdominal surgery (cholecystectomy and appendectomy can be tolerated when performed at least one year previously)
• Pregnancy or breast feeding
• Current or past history of alcohol dependence
• Based on lack of adequate scientific evidence to predict drug-drug interaction in vivo, current use of strong inhibitors or inducers for CYP enzymes and participants are instructed not to take any medications that are strong inhibitors or inducers for CYP enzymes during the course of the study
• Vulnerable Subjects. The study will not include vulnerable subjects (such as, those with limited autonomy or those in subordinate hierarchical positions). Children, pregnant women, nursing home residents or other institutionalized persons, students, employees, fetuses, prisoners, and persons with decisional incapacity will not be included.