An Open-label, 6-arm Parallel Group, Single-center Preference Clinical Study on the Effects of Smoking Cessation or Switching From Cigarette Smoking to the Tobacco Heating System (THS) in Adult Smokers Who Have Been Diagnosed With Inflammatory Bowel Disease (IBD) and Are Under Treatment.

The main goal of this study is to evaluate the effects of smoking cessation or switching from cigarette smoking to THS (tobacco heat system) on the clinical course of UC (ulcerative colitis) and CD (Crohn´s disease) in adult smokers who were diagnosed with IBD and are under treatment.

Measures using validated/standardized assessment methods and self-reported outcomes will be assessed in patients who stop smoking or switch from smoking to using THS over the investigational period of 6 months, relative to smokers who continue smoking cigarettes.