Swiss Kriss is an herbal laxative used to treat mild constipation and improve bowel regularity. The tablets contain peach and strawberry leaves, anise and caraway seeds and hibiscus and calendula flowers. Swiss Kriss flakes contain these same ingredients as well as juniper berries, licorice root, fennel, dandelion, papaya, lemon verbena, centaury, cyani and parsley. Sun-dried senna leaves constitute the only active ingredient in either product. Swiss Kriss is well-tolerated by most people but, like any medicinal preparation, there are potential side effects associated with its use. Check with your doctor to see if Swiss Kriss is appropriate for you.
Senna leaves are obtained from plants belonging to the "Cassia" genus. They contain compounds called sennosides which belong to a family of chemicals called anthranoids. The "Physicians' Desk Reference for Herbal Medicines" describes the sennosides as stimulatory laxatives whose actions stem from their ability to inhibit water and electrolyte absorption from your colon. This increases the volume and pressure of your intestinal contents, which enhances colonic motility and triggers contractions that propel your stools forward. Sennosides also stimulate secretion of chloride ions from your intestinal lining, which draws more water into your colon.
Constipation is characterized by a lack of normal bowel activity and an increase in the firmness of your stools. Your colon removes water from fecal material that is retained in your intestine for long periods of time, causing it to become hardened and compacted. This material is not readily moved through your colon, which must contract more forcefully to evacuate the retained stool. When you take a stimulating laxative that increases bowel motility, you may experience some cramping until the consistency of your stools normalizes.
Some studies evaluating the long-term effects of sennosides in humans have raised concerns about electrolyte imbalances, loss of normal colonic musculature, damage to the nerves that control intestinal motion and even cancer. For example, a study published in the June 1998 "Journal of Clinical Gastroenterology" suggested that chronic use of senna-containing laxatives led to a loss of normal colonic anatomy and possible neuronal damage, a condition known as "cathartic colon." However, an extensive review in the 2009 issue of "Journal of Toxicology" reported that there is no convincing evidence that sennosides cause cathartic colon or increase the risk for cancer in humans, nor do they promote the growth of tumors in rats at doses up to 300 mg per kilogram per day -- approximately 21 grams in a 150-lb human.
As is the case with any herbal product, you may be allergic to one of Swiss Kriss' ingredients, or you could develop an allergy during its use. Symptoms of allergic reactions to ingested herbal preparations include skin rashes or hives, runny nose, itchy throat, cough, wheezing, vomiting, severe cramping and diarrhea. Do not use Swiss Kriss if you are allergic to any of its ingredients or if you already have abdominal pain or vomiting. Do not use Swiss Kriss or any other laxative for more than a week or two without your physician's advice. Persistent constipation or irregularity may indicate an underlying medical problem that merits medical attention.