This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Death and Investigations, Subject name: Forensic Medicine
Bacteria most commonly involved in bowel decomposition after death is - 
Select and explain. 
A. Streptococcus pyogens, B. Clostridium welchii, C. Pseudomonas aerogenosa, D. None
B: Clostridium welchii
Answer: B: Clostridium welchii 
Explanation: Ans. is 'b' i.e. Clostridium welchii o Bowel decomposition is brought about by aerobic and anaerobic bacteria present in small intestine (e.g. C. welchii, staphylococcus, E.coli etc.) which release enzymes (especially lipase and lecithinase) which act on body to cause breakdown.