Removing 6 ft (less than 2 m) from the small intestine should not cause any serous disorders of its function. The remaining bowel, about 13 ft in lenth, should provide proper function of the intestinal tract. Removing more than 2/3 of the small intestine can cause the so called short bowel syndrome which can be manifested with abdominal pain, diarrhea, malnutrition and weight loss.

In your case diarrhea could be a result of some other reasons beside intestinal resection.

Can you tell me how many times you have bowel movement per day and are there fats present in the stool? (Fats give the stool a specific stinky smell)

Have you ever performed a microbiological examination of the stool and blood analyzes?