I have upper abdomen (center) discomfort and mild pain after bowel movement and last for 1 to 2 hours. however pain goes away with tums (calcium carbonate).

Tums (calcium carbonate): Tums, (calcium carbonate) an antacid, May relieve an inflamed stomach or duodenal lining or peptic ulcer but don't generally affect intestinal activity. These conditions are not affected usually by the act of defecation. If your discomfort persists, consult your physician or a gastroenterologist for evaluation.

Many things can: cause abdominal pain. Sometimes other symptoms can help point you in the right direction. Nausea, vomiting, bleeding while defecating, acute or subtle onset, relationship with food/bowel movement, location of pain if changing, pattern of pain, fever, all these symptoms will help with diagnosis. If pain goes away with Tums, (calcium carbonate) it is likely gastritis from acid or stomach ulcer.