Hello!
Thank you for the query.
His diarrhea can be caused by chronic Nexium intake, diet (milk is generally hardly digestible for humans), chronic bowels infection or even partial bowels obstruction due to
colon cancer or inflammatory bowels disease.
Nexium is a medicine which blocks stomach acid secretion. Stomach acid kills many bacteria and protects digestive tract from infection. When there is no stomach acid, bacteria can infect intestines and cause
chronic diarrhea.
Milk and too much vegetables can cause chronic diarrhea due to lactulose intolerance for example.
Chronic bacterial infection can be related to the Nexium intake or some antibiotics intake in the past for example.
Partial bowels obstruction should be also ruled out, especially at the age of 82. Colon cancer can cause such symptoms for many years.
Weight loss,
blood in stool, bloating can also appear.
I suggest your friend to try to stop taking Nexium (consult this with his doctor), stop drinking so much milk and try mild diet. Probiotics should be added to the diet. If this wont help, stool tests and
colonoscopy should be done.
Hope this will help.
Regards.