The famed abbess and healer St Hildegard von Bingen mentioned in her works that constant respiratory disorders such as runny nose, rhinitis etc are caused by weak stomach and intestines. She recommended taking a ginger purging cookie as one the remedies to strengthen digestion and rid the body of bad humors.
She was right. Modern functional medicine has confirmed that most respiratory ailments are due to weak digestion. This led further to food intolerance. For this reason, many of my treatments start from the gut.
However, weak digestion can be caused by some underlying psychological issues such as depression (which often is denied). A holistic treatment therefore is necessary.