Occasionally, steam users report an increase in cramping after vaginal steaming. The majority of situations where this happens, the person is using plugging products such as tampons impeding menstrual flow and causing the uterus to contract (cramp) to try to cleanse. Cramps occur when uterus contracts to expel menses or clots.
If someone has a substantial amount of old residue built up in their womb, it appears that steaming helps to loosen that old residue which means that the following period may have a lot of old residue flow out.
This result is an expected and necessary step to relieving the root cause of menstrual cramps, however if the flow is impeded by plug products then the cleanse cannot happen and cramps may be more sensitive.
If the steam user understands that the period is a uterine cleanse and implements the 5 principles of womb cleanse care (prioritize rest, do not plug, keep the womb warm, hydrate/nourish, avoid inversions/exercise/intercourse), they usually will not experience cramps. However, there may be times when the uterus is clearing out a large clot and in such cases some amount of cramping or discomfort is inevitable.