Fluctuations in blood sugar levels can happen in diabetes, but repeated episodes of very high or low readings usually suggest that your treatment or diet may need adjustment. The episodes of stomach upset with loose motions and lower abdominal pain are not a typical direct symptom of diabetes and may be due to infections, food intolerance, or sometimes side effects of medications such as metformin. Some people with diabetes can also have gut-related problems, but this needs proper assessment to confirm. It is important to keep a record of your blood sugar levels and gastrointestinal symptoms and discuss them with your doctor for proper evaluation and adjustment of treatment.