What is the ruling of Islamic law on a husband remaining with his wife who suffers pain during intercourse due to chronic inflammation, while he continues to suffer from sexual deprivation and cannot practice polygyny in his country?

What the wife feels is not considered an illness that necessitates a choice for the husband because she became pregnant and gave birth. The illness that necessitates a choice is that which prevents intercourse or its pleasure, as stated in Hashiyat al-Adawi and Sharh Mayarah al-Fassi. It is advised to keep the wife and strive to treat the illness.