Can montmorillonite powder be applied for severe diaper rash?

In general, severe diaper rash should not be treated with smectite powder. The detailed explanation is as follows:

Smectite powder is an antidiarrheal medication primarily used to treat acute and chronic diarrhea in adults and children. Diaper rash is a common skin condition in infants, mostly occurring in babies aged 1–4 months. It mainly presents as redness of the buttocks and dilated blood vessels on the inner thighs. In severe cases, it may also involve skin breakdown, erosion, and bleeding. Severe diaper rash may result from prolonged moisture in the buttock area combined with irritation from urine and feces. Smectite powder is an oral antidiarrheal agent and is not intended for topical use in treating skin conditions—diaper rash being one such condition. Applying smectite powder to diaper rash may trigger allergic reactions and worsen the condition; therefore, smectite powder should not be used for severe diaper rash.

If diaper rash occurs, it is recommended to use topical medications such as compound cod liver oil zinc oxide ointment or compound algininate cream under medical guidance, while maintaining good personal hygiene for the infant.