Ihraam

Wearing underwear in the state of ihraam due to urine incontinence

Q: My father has a small problem with old age and urine drops. He says straight after he goes to the toilet, about 5 or 10 mins after, he has some trouble with few drops. Then it subsides. 

He usually uses tissue with his underwear for a few minutes after going to the bathroom in case any drops come out and then discards it a short while later. 

He's concerned with ihraam and how would he manage. 

What would be suggested? Is there an option to wear underwear and pay damm? Or is there any alternative.