parasites in intestines. indigestion, germs, infection and viruses in body. intestinal walls and viral inflammation under a micros

anatomy bacteria body bowel cell clinic closeup colon digestive disease epidemic flu gastric gastritis germs health healthcare ill illustration immune immunity indigestion infection inflammation intestinal intestines intoxication irritation macro medical medicine microbe microbiology microorganism microscope microscopic organism pain pandemic parasites parasitic protection research rotavirus science stomach toxin tract villi viral virology virus viruses walls