A comparative study found that inducing three sputum samples is more sensitive than three gastric washings.

After about four days, the staff was able to confirm the ascariasis diagnosis upon isolating live larvae, about 4 mm long, in the sputum and gastric washings.

Professor Walery Jaworski of the Jagiellonian University in Kraków investigated sediments of gastric washings obtained from humans in 1899.

In patients incapable of producing a sputum sample, common alternative sample sources for diagnosing pulmonary tuberculosis include gastric washings, laryngeal swab, bronchoscopy (with bronchoalveolar lavage, bronchial washings, and/or transbronchial biopsy), and fine needle aspiration (transtracheal or transbronchial).