Hi, and thanks for your medical question on eHealth forum!
You could be suffering from an inflammatory bowel condition such as Celiac Disease/Ulcerative Colitis/Irritable Bowel Syndrome/ Crohnâs disease. All these result in tender abdomen, loose stool or loose stools alternating with constipation, abdominal distention, cramps etc.It can also be severe acidity. Parasites in the gut like threadworm, tape worm, giardiasis etc can behave this way. Hence a stool test is a must.
Problems of gall bladder and liver or that of pancreas too cannot be ignored. Possibility of H pylori infection should be looked into by carbon urea breath test. Proper medication and diet control is needed for recovery. Please discuss this with your GI specialist. Hope this helps. Take care!