An NHS doctor explained common, seemingly strange symptoms like eyelid twitching and the urge to defecate after drinking coffee. Eyelid twitching, known as myochimia, is often triggered by caffeine, fatigue, or stress and is usually harmless unless persistent or spreading. The urge to defecate after coffee consumption is attributed to the gastrocolic reflex, a natural digestive response. The doctor advises consulting a GP if symptoms are persistent or affect quality of life.