Is having gas during mensuration fine? how can it be cured?

Try different foods: A little gas is ok but not a lot. Since we don't digest the fiber we eat, intestinal bacteria feed on excess fiber and make gas as a byproduct. Another reason may be lactose intolerance, in which one can't digest the lactose (milk sugar) he eats, leading to gas. During the menstrual cycle, some women have changes in the speed of food passing the gut (slower = constipation), which can increase gas.