Nicotine affects neurological, neuromuscular, cardiovascular, respiratory, immunological and gastrointestinal systems. Magnesium deficiency may result from gastrointestinal or kidney causes. Lactose intolerance does not cause damage to the gastrointestinal tract. Adverse effects include headache and gastrointestinal discomfort. Solanine poisoning is primarily displayed by gastrointestinal and neurological disorders. This motility problem results from atrophy of the gastrointestinal tract wall smooth muscle. Subcutaneous emphysema can result from puncture of parts of the respiratory or gastrointestinal systems. Methyldopa exhibits variable absorption from the gastrointestinal tract. Excisional biopsies of skin lesions and gastrointestinal polyps are very common. Ciguatera poisoning is characterised by neurological, gastrointestinal, and cardiovascular problems. Gut organoids refer to organoids that recapitulate structures of the gastrointestinal tract. Common interoceptive sensations related to the gastrointestinal and genitourinary systems are hunger and fullness. There are a number of non-infectious causes of inflammation of the gastrointestinal tract. Celiac disease presents the strongest associations to gastrointestinal and lymphoproliferative cancers. They are resistant to degradation by enzymes found in the gastrointestinal tract.