Meaning of dà biàn:
大便
to defecate
Tā gǎnjué dùzi bù shūfú, suǒyǐ qù cèsuǒ dàbiàn.
他感觉肚子不舒服,所以去厕所大便。
He felt his stomach was uncomfortable, so he went to the bathroom to defecate.
excrement; feces
Yīshēng jiànyì háizi duō chī shūcài yǐ gǎishàn tā de xiāohuà xìtǒng, yīnwèi tā zuìjìn chángcháng dàbiàn bù chàng.
医生建议孩子多吃蔬菜以改善他的消化系统,因为他最近常常大便不畅。
The doctor advises the child to eat more vegetables to improve his digestive system because he has been having trouble with his bowel movements recently.