Allergies

• Some people are allergic to senna tea. Some users have experienced serious allergic reactions. You should always take senna tea in small amounts the first time and watch for reactions such as swelling of the tongue face or lips and difficulty breathing and swallowing.
  
  

Digestive Issues

• Senna tea can worsen digestive issues instead of improving them. These problems are often from overuse. The digestive issues include chronic diarrhea, nausea and stomach cramps. This can lead to dehydration and an electrolyte balance disturbance, which can be fatal.
  
  

Laxative Dependency

• Overuse of senna tea can damage the colon and rectum as they become desensitized to the need to defecate. This will cause a strong dependency of more laxatives and cause a recurring long-term issue.
  
  

Finger and Toe Enlargement

• An odd side effect of senna use is the growth of the fingers and toes, which become clubbed. This is visible in people with anorexia who abuse the herb. Fortunately, the symptom is reversible when use is discontinued.
  
  

Organ Injury

• Overuse of senna tea in known to damage the organs. It can cause Pseudomelanosis coli, a condition that turns the intestines black. This may can cause colorectal cancer. It may cause liver enzyme altercation, chronic liver disease and liver failure. Senna tea can also damage the kidneys and cause renal failure.
  
  

Drug Interactions

• Anyone who senna tea must inform their doctor to avoid dangerous drug interactions. There are at lease 123 drugs that cause bad reactions when mixed used with senna tea. Some common drugs that react with senna tea are aspirin, Lasix, Lexapro, Milk of Magnesia, Prilosec and Tylenol. Vitamins C and D may also cause adverse drug interactions when taken with senna tea.
  
  

Pregnancy

• Pregnant women should not take senna tea because it can cause premature contractions and miscarrage. Lactating mothers should also avoid it to prevent it from causing a laxative effect in the baby's digestive system.