Colpermin IBS Relief Capsules Colpermin IBS Relief Capsules relieve the spasms & cramps which occur in the large bowel in Irritable Bowel Syndrome (IBS). They contain peppermint oil, an antispasmodic which relaxes the spasm of the bowel wall. This relieves pain & allows pockets of gas, which may have made you feel bloated, to pass along the bowel & out of the body.