Heartburn and gastric reflux sound like your stomach energy is going upwards, like a lack of cooling. Trapped gas sounds more like a yang weakness, but I can only speculate. If the problem is a lack of fire, then general weakness and fatigue are more likely, whereas if the problem is related to the Moon, then you may feel like it is hard to let things go, whether emotionally or physically (referring to your bowels), feel comfortable, or fall asleep easily. The sign of Virgo also rules the intestines so placements with this sign would also factor in.
Yoga would help, although extra effort towards the intestines in any of these solutions would likely be required. If it is hard for you to maintain a steady routine, then yoga + acupoints like large intestine 4 would probably be your best bet at raising and directing healing energy to the intestines to resolve this.
Fire is always the source of vitality, but the strength of these other placements determines the "efficiency" of how the energy is received to the associated part of the body. A Moon Square would help resolve any imbalance, but it also cannot directly replace low vitality. With Mars in Leo, and the Sun soon in Sag, as well as the Taurus Esbat, you could start a healing working, and/or do the ritual of any healing God as you get time.