A diet low in FODMAPs («a Low FODMAP Diet») is scientifically proven1, and is now recommended internationally, as the most effective dietary therapy to manage symtpoms of Irritable Bowel Syndrome (IBS). (fodmapfriendly.com)
Note that this is just a «screening test» - it checks for early possible symtpoms but doesn't measure whether you actually are geting schizophrenia. (schizophrenia.com)
Having POTs like symtpom after hot bath may be due to blood pooling, and that means the underlying autonomic nervous system may be in trouble. (drlam.com)