2 sentences for 苦痛 (kǔ​tòng — suffering)

1. 感受他们的苦痛吧。

   gǎn​shòu tā​men de kǔ​tòng ba.

   Feel their pain.

   Source: OpenSubtitles

2. 他内心的苦痛是旁人无法体会的。

   tā nèi​xīn de kǔ​tòng shì páng​rén wú​fǎ tǐ​huì de.

   The pain in his heart is something others cannot experience or understand.

   Source: Dong Chinese Dictionary