3 sentences

1. 他感到下体有些不适，决定去医院检查。

   tā gǎn​dào xià​tǐ yǒu​xiē bù​shì, jué​dìng qù yī​yuàn jiǎn​chá.

   He felt some discomfort in his lower body and decided to go to the hospital for a checkup.

   Source: Dong Chinese Dictionary

2. 他在事故中伤到了脊椎，导致下体完全瘫痪。

   tā zài shì​gù zhōng shāng dào le jǐ​zhuī, dǎo​zhì xià​tǐ wán​quán tān​huàn.

   He injured his spine in the accident, resulting in complete paralysis of his lower body.

   Source: Dong Chinese Dictionary

3. 这株植物的下体部分深扎在土壤中，吸收充足的水分。

   zhè zhū zhí​wù de xià​tǐ bù​fen shēn zhā zài tǔ​rǎng zhōng, xī​shōu chōng​zú de shuǐ​fèn.

   The lower part of this plant is deeply rooted in the soil, absorbing plenty of water.

   Source: Dong Chinese Dictionary