The bowel problems of diarrhea and nausea after eating and white coating of the tongue may be due to GERD(gastro esophageal reflux disease), acute non-GI infections (pyelonephritis, pneumonia),gastroenteritis,liver
diseases, pancreatic disorder,peptic disease of upper GI tract,gastric carcinoma,CNS
diseases like infections, tumors, multiple sclerosis and metabolic disturbances like diabetes and adrenal insufficiency.
Similarly white tongue is found in GI and liver disorders.