Hi welcome to health care magic forum, being a chronic disease the course of the disease will be like this, getting resistance to the drugs, we will consider few nom medical factors for the relief of these symptoms. The way of your treatment is good and any other substitutes will have side effects and resistance as these drugs.
It is irritable bowel syndrome
. The irritation could be central from the nervous origin or local of intestines.
Avoid thinking about the disease, any tensions, avogations, etc.
Most important thing the diet regulation. Avoid taking more of spices, chillies, junk foods, oily foods, and nonvegitarian foods for at least one month. Most probably you will be relieved of the symptoms.
Take more of green leafy vegetables fruits and juices, and take more water.
Wishing for a quick recovery, and thanks for calling.