1875-1965 administration alternativetreatment bioavailability careandhygiene complementarytherapies diettherapy diseases dosage drugdeliverysystems drugeffects drugs fasting franzxaver gastrointestinaldiseases gastrointestinalhormones gastrointestinalmotility gastrointestinalsystem intestinalabsorption intestines mayr metabolism methods motility neurotransmitters pharmaceuticalpreparations physiologicaleffect therapeuticuse therapy wi102d7931989 wi140