What Causes Severe Gastritis Along With Loose Bowels?

Hi Doctor.. I m suffering from gastric problems. Loose motion 2 to 3 times a day. And also feels very weak nowadays. I m eating well but nothing is reflecting. I consulted with a doctor sometime back. He gave me secnidazole and enderogermina. It was a temporary solution. But again i m having same problems. It was happening fo rquite sometime. Now I got another set of medicines. it includes colospa,bifilac, librax and razo. Is it ok if I take these. Any other check up do I need to take?