You may have been retaining water from histamine
You may have been retaining water from histamine. Now that you got it under control with Zyrtec, you eliminated that water....................................................Histamine causes water retention leading to bloating and abdominal swelling. If you have ever been stung by an insect or developed an itchy red lump after a mosquito bite, you will be familiar with the effects of histamine. Histamine widens the joins between the cells which line your smallest blood vessels, known as your capillaries. This makes them leak both water and protein into your “tissue spaces” – the area surrounding the cells of tissues such as flesh, organs and intestines. If the protein cannot be removed from your tissue spaces, it will stay there, attracting water.
Poor digestion and taking antibiotics can cause changes in your intestines which lead to a lot of histamine being produced in this area. Sometimes eating yoghurt and probiotics can help to reduce this problem, but if it has been going on for some time these measures may not be effective on their own.